Note: This page contains sample records for the topic thin film superconductor from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

The formation and analysis of thin film high temperature superconductors  

SciTech Connect

Thin films of high temperature superconductors have been fabricated using a variety of physical vapor deposition techniques. Recent results of HTS thin films produced by coevaporation, sputtering and laser deposition will be briefly reviewed. In addition some examples of the utility of high energy ion backscattering for the analysis of film stoichiometry will be given. 34 refs., 6 figs.

Nastasi, M.; Muenchausen, R.E.; Arendt, P.N.

1989-01-01

2

Raman measurements on Bi-based superconductor thin films  

Microsoft Academic Search

The copper-bismuth based superconductor has attracted much interest because of its high critical temperature, specially with the partial substitution of Pb in Bi sites, since it indicates stabilization in the 2223-phase. We present a Raman study in Bi-Pb-Sr-Ca-Cu-O thin films grown on MgO substrates by spray pyrolysis technique. The thin films were prepared by the two steps procedure: deposition of

Concepcion Mejia-Garcia; Elvia Diaz-Valdes; Gerardo Contreras-Puente; Milan Jergel

2000-01-01

3

Wear and friction of thin film high temperature oxide superconductors  

SciTech Connect

We have examined the sliding properties of a Nd-Fe-B magnet against a thin film YBa/sub 2/Cu/sub 3/O/sub 7/ superconductor. Pin-on-disk experiments were performed at room temperature and in normal air using a 10 mm magnetic Nd-Fe-B ball loaded to 31.22 g and a sliding speed of approximately 0.57 cm/sec. Such condition produced a steady state friction coefficient of 1.1 +- 0.3. Wear rate measurements indicated that Nd-Fe-B will wear YBa/sub 2/Cu/sub 3/O/sub 7/ at a rate 1.3 /times/ 10/sup /minus/14/ m/sup 3//m and that the Nd-Fe-B/YBa/sub 2/Cu/sub 3/O/sub 7/ sliding system possess a wear coefficient of 4.2 /times/ 10/sup /minus/14/ m/sup 3//Nm. These unusually high values appear to be the result of both abrasive and adhesive wear. Adhesion between the sliding surfaces is most probably enhanced by the oxygen reactivity of the pin material and the high oxygen content in the superconductor. 3 refs., 5 figs.

Nastasi, M.; Hirvonen, J.-P.; Toivanen, R.O.

1989-01-01

4

Electrical Properties of Metal Oxide Thin Films: High Temperature Superconductors and Ferroelectrics  

Microsoft Academic Search

Transition metal oxides possess intriguing electronic properties with many potential applications. These materials include the high transition temperature superconductors and ferroelectric oxides. The properties of these materials depend strongly on the oxygen and cation stoichiometries, which modulate the charge carrier concentration. For this study, thin films of high-T_{c } superconductors and ferroelectrics were deposited by metal-organic chemical vapor deposition processes.

Jon Lindsay Schindler

1995-01-01

5

Pseudogap in a thin film of a conventional superconductor.  

SciTech Connect

A superconducting state is characterized by the gap in the electronic density of states, which vanishes at the superconducting transition temperature T{sub c}. It was discovered that in high-temperature superconductors, a noticeable depression in the density of states, the pseudogap, still remains even at temperatures above T{sub c}. Here, we show that a pseudogap exists in a conventional superconductor, ultrathin titanium nitride films, over a wide range of temperatures above T{sub c}. Our study reveals that this pseudogap state is induced by superconducting fluctuations and favoured by two-dimensionality and by the proximity to the transition to the insulating state. A general character of the observed phenomenon provides a powerful tool to discriminate between fluctuations as the origin of the pseudogap state and other contributions in the layered high-temperature superconductor compounds.

Sacepe, B.; Chapelier, C.; Baturina, T. I.; Vinokur, V. M.; Baklanov, M. R.; Sanquer, M. (Materials Science Division); (CEA-INAC/UJF-Grenoble); (A.V. Rzhanov Inst. Semiconductor Physics); (IMEC)

2010-12-01

6

Pseudogap in a thin film of a conventional superconductor.  

PubMed

A superconducting state is characterized by the gap in the electronic density of states, which vanishes at the superconducting transition temperature T(c). It was discovered that in high-temperature superconductors, a noticeable depression in the density of states, the pseudogap, still remains even at temperatures above T(c). Here, we show that a pseudogap exists in a conventional superconductor, ultrathin titanium nitride films, over a wide range of temperatures above T(c). Our study reveals that this pseudogap state is induced by superconducting fluctuations and favoured by two-dimensionality and by the proximity to the transition to the insulating state. A general character of the observed phenomenon provides a powerful tool to discriminate between fluctuations as the origin of the pseudogap state and other contributions in the layered high-temperature superconductor compounds. PMID:21266990

Sacépé, Benjamin; Chapelier, Claude; Baturina, Tatyana I; Vinokur, Valerii M; Baklanov, Mikhail R; Sanquer, Marc

2010-01-01

7

In-situ optical diagnosis during pulsed laser deposition of high-Tc superconductor thin films  

Microsoft Academic Search

A new concept to achieve real-time optical diagnosis during pulsed laser deposition (PLD) of multilayered high temperature superconductor (HTS) thin films was developed. We have constructed a prototype instrument, which combines ultraviolet (UV) and visible (VIS) emission spectroscopy of the substrate and thin-film structure. The UV\\/VIS emission spectroscopy offers a convenient tool for monitoring the excited atoms, molecules, and ions

Q. Li; S. Liu; D. B. Fenner; J. Luo; W. D. Hamblen; J. Haigis

1995-01-01

8

Size effect on the thermal conductivity of high-Tc thin-film superconductors  

Microsoft Academic Search

Using the kinetic theory approximation and reported data, this study shows that at low temperatures, the phonon mean free path in polycrystalline ceramic YBa2Cu3O7 can be of the order of the thickness of thin-film superconductors. In this case, boundary scattering reduces the thermal conductivity with decreasing film thickness. A simple method accounts for the size effect on conduction in thin

M. I. Flik; C. L. Tien

1990-01-01

9

Superconductor—Insulator Transitions in Pure Polycrystalline Nb Thin Films  

NASA Astrophysics Data System (ADS)

We report on a study of the transport properties of Nb thin films. By varying the thickness of the films from 263 Å to 25 Å, we observed a depression of the superconductivity. Magnetic field was also applied up to 6 T, inducing the disappearance of the superconductivity and the onset of an insulating behavior. The results were compared to those we have already obtained on a highly disordered system, a-NbxSi1-x, to understand whether the same mechanisms for the disappearance of the superconductivity could be at play in pure metallic thin films and in highly disordered systems.

Couedo, F.; Crauste, O.; Bergé, L.; Dolgorouky, Y.; Marrache-Kikuchi, C.; Dumoulin, L.

2012-12-01

10

High-Temperature Superconductor Thin Films and Devices  

Microsoft Academic Search

High-T_{rm c} YBaCuO thin films have been successfully fabricated by off-axis RF magnetron sputtering from a single 5 cm YBa _2Cu_3O _{6.9} target without post-deposition heat treatment required. The critical temperatures are typically 83-89 K for the films on MgO substrates and 85 -89 K or SrTiO_3 substrates. The films on MgO substrates display critical current densities as high as

David Kun Chin

1990-01-01

11

Highly Sensitive Infrared Detector Fabricated with Thin Film of High Tc Y-Ba-Cu-O Superconductor. Phase 1.  

National Technical Information Service (NTIS)

In the phase I study of the project entitled 'Highly Sensitive Infrared Detector Fabricated with Thin Film of High Tc Y-Ba-Cu-O Superconductor using Pulsed Laser', we have successfully deposited thin films of Y-Ba-Cu-O on MgO/TcO2 substrate by plasma assi...

R. Rao

1989-01-01

12

Thermal treatment of superconductor thin film of the BSCCO system using domestic microwave oven  

NASA Astrophysics Data System (ADS)

In this work, we report the preparation of a superconductor thin film of the BSCCO system using a good quality powder with nominal composition Bi1.8Pb0.4Sr2CaCu2Ox which was thermally treated using a domestic microwave oven (2.45 GHz, 800 W). This film was grew on a single crystal of LaAlO3 (1 0 0) substrate and exhibited a crystalline structure with the c-axis perpendicular to the plane of the substrate. An onset superconducting transition temperature was measured at 80 K.

Silveira, J. B.; Carvalho, C. L.; Torsoni, G. B.; Aquino, H. A.; Zadorosny, R.

2012-08-01

13

Magnetron deposition of ceramic oxide-superconductor thin films  

SciTech Connect

This patent describes an apparatus for depositing a superconducting thin film of metal oxide ceramic materials onto the outer surface of a substrate. It comprises: first and second vacuum chamber means; means for positioning a substrate within the first and second vacuum chamber means; a cylindrical magnetron positioned within the first vacuum chamber means; a disc-shaped cold cathode positioned within the first vacuum chamber means and having an axis that is substantially coincident with the longitudinal axis of the substrate; a ring-shaped cold cathode positioned within the second vacuum chamber means and having an axis that is substantially coincident with the longitudinal axis of the substrate; power supply means for applying selected operating voltages to the cylindrical cathode, cylindrical anode, cylindrical solenoid, disc-shaped cold cathode, and ring-shaped cold cathode; vacuum control means, including differential pumping means, coupled to the first and second vacuum chamber means for establishing and maintaining desired vacuum levels within the first and second vacuum chamber means; and gas port means.

Collins, G.J.; McNeil, J.R.; Yu, Z.G.

1990-10-02

14

Magnetron deposition of ceramic oxide-superconductor thin films  

SciTech Connect

A method for depositing a superconducting thin film of metal oxide ceramic materials onto the outer surface of a substrate, the method comprising: introducing a substrate to be coated into a vacuum chamber apparatus that includes a cylindrical magnetron having a longitudinal axis substantially coincident with a longitudinal axis of the substrate, having a cylindrical extraction grid coaxially positioned with respect to the substrate, having a cylindrical anode of diameter greater than that of the cylindrical extraction grid and coaxially positioned with respect to the substrate, having a cylindrical cathode of diameter greater than that of the cylindrical anode and coaxially positioned with respect to the substrate and the cylindrical anode, the cylindrical cathode comprising at least three metal materials, and having a cylindrical solenoid of diameter greater than that of the cylindrical cathode and coaxially positioned with respect to the substrate, the cylindrical extraction grid, the cylindrical cathode, and the cylindrical anode; establishing a controlled gas atmosphere within the vacuum chamber apparatus, the controlled gas atmosphere including a sputter gas comprising an inert gas and a reactive gas mixture comprising at least oxygen.

Collins, G.J.; McNeil, J.R.; Yu, Z.

1989-06-27

15

Field-induced reentrant superconductivity in thin films of nodal superconductors  

NASA Astrophysics Data System (ADS)

Previous work on nodal d-wave superconductors has shown that a Fulde-Ferrell-Larkin-Ovchinnikov- (FFLO-) like superconducting (SC) state, which is modulated along the film plane, can be realized with no magnetic field when quasiparticles acquire an additional linear term in the wave vector in their dispersion. In the present work, the stability of such a modulated SC state in an artificial film against an applied magnetic field is studied. As a reflection of the presence of two FFLO-like states of different origins, one close to zero field and the other at the high-field end, in a single field vs temperature phase diagram of thin films, the conventional SC state, which is uniform along the film plane, generally tends to appear as a reentrant ordered phase bounded by the normal phase in lower fields.

Hachiya, M.; Aoyama, K.; Ikeda, R.

2013-08-01

16

Superconductor-Metal-Insulator transition in two dimensional Ta thin Films  

NASA Astrophysics Data System (ADS)

Superconductor-insulator transition has been induced by tuning film thickness or magnetic field. Recent electrical transport measurements of MoGe, Bi, Ta thin films revealed an interesting intermediate metallic phase which intervened superconducting and insulating phases at certain range of magnetic field. Especially, Ta thin films show the characteristic IV behavior at each phase and the disorder tuned intermediate metallic phase [Y. Li, C. L. Vicente, and J. Yoon, Physical Review B 81, 020505 (2010)]. This unexpected metallic phase can be interpreted as a consequence of vortex motion or contribution of fermionic quasiparticles. In this presentation, we report the scaling behavior during the transitions in Ta thin film as well as the transport measurements in various phases. Critical exponents v and z are obtained in samples with wide ranges of disorder. These results reveal new universality class appears when disorder exceeds a critical value. Dynamical exponent z of Superconducting sample is found to be 1, which is consistent with theoretical prediction of unity. z in a metallic sample is suddenly increased to be approximately 2.5. This critical exponent is much larger than the value found in other system and theoretical prediction.

Park, Sun-Gyu; Kim, Eunseong

2013-03-01

17

Optical properties of TiN thin films close to the superconductor-insulator transition.  

SciTech Connect

We present the intrinsic optical properties over a broad spectral range of TiN thin films deposited on an Si/SiO{sub 2} substrate. We analyze the measured reflectivity spectra of the film-substrate multilayer structure within a well-establish procedure based on the Fresnel equation and extract the real part of the optical conductivity of TiN. We identify the metallic contribution as well as the finite energy excitations and disentangle the spectral weight distribution among them. The absorption spectrum of TiN bears some similarities with the electrodynamic response observed in the normal state of the high-temperature superconductors. Particularly, a mid-infrared feature in the optical conductivity is quite reminiscent of a pseudogap-like excitation.

Pfuner, F.; Degiorgi, L.; Baturina, T. I.; Vinokur, V. M.; Baklanov, M. R.; Materials Science Division; ETH Zurich; Inst. Semiconductor Physics; IMEC Kapeldreef

2009-11-10

18

High-frequency applications of high-temperature superconductor thin films  

NASA Astrophysics Data System (ADS)

High-temperature superconducting thin films offer unique properties which can be utilized for a variety of high-frequency device applications in many areas related to the strongly progressing market of information technology. One important property is an exceptionally low level of microwave absorption at temperatures attainable with low power cryocoolers. This unique property has initiated the development of various novel type of microwave devices and commercialized subsystems with special emphasis on application in advanced microwave communication systems. The second important achievement related to efforts in oxide thin and multilayer technology was the reproducible fabrication of low-noise Josephson junctions in high-temperature superconducting thin films. As a consequence of this achievement, several novel nonlinear high-frequency devices, most of them exploiting the unique features of the ac Josephson effect, have been developed and found to exhibit challenging properties to be utilized in basic metrology and Terahertz technology. On the longer timescale, the achievements in integrated high-temperature superconductor circuit technology may offer a strong potential for the development of digital devices with possible clock frequencies in the range of 100 GHz.

Klein, N.

2002-10-01

19

Q factor of megahertz LC circuits based on thin films of YBaCuO high-temperature superconductor  

Microsoft Academic Search

High-frequency properties of resonant structures based on thin films of YBa2Cu3O7–? high-temperature superconductor are studied experimentally in the frequency range 30–100 MHz. The structures planar induction\\u000a coils with a self-capacitance fabricated on neodymium gallate and lanthanum aluminate substrates. The unloaded Q factor of\\u000a the circuits exceeds 2 × 105 at 77 K and 40 MHz. Possible loss mechanisms that determine

D. V. Masterov; S. A. Pavlov; A. E. Parafin

2008-01-01

20

Thin films  

NSDL National Science Digital Library

This simulation illustrates the behavior of thin films for reflected light. The user can change the angle of the incident beam, the thickness of the thin film and the type of thin film used. Two types of thin film are allowed.

Renault, Pascal

2009-12-04

21

Q factor of megahertz LC circuits based on thin films of YBaCuO high-temperature superconductor  

NASA Astrophysics Data System (ADS)

High-frequency properties of resonant structures based on thin films of YBa2Cu3O7 ? high-temperature superconductor are studied experimentally in the frequency range 30 100 MHz. The structures planar induction coils with a self-capacitance fabricated on neodymium gallate and lanthanum aluminate substrates. The unloaded Q factor of the circuits exceeds 2 × 105 at 77 K and 40 MHz. Possible loss mechanisms that determine the Q factor of the superconducting resonant structures in the megahertz range are considered.

Masterov, D. V.; Pavlov, S. A.; Parafin, A. E.

2008-05-01

22

Raman scattering study of phonons in Bi-based superconductor thin films  

Microsoft Academic Search

Raman spectra were obtained from samples of Bi–Pb–Sr–Ca–Cu–O (BPSCCO) thin films after varying several growth parameters, such as covering material, annealing time (tR), annealing temperature (TR), and nominal lead content (x). Thin films with the nominal composition Bi1.4PbxSr2Ca2Cu3O? were grown on MgO substrates by a spray pyrolysis technique, followed by a solid state reaction. The results of Raman scattering measurements

Concepción Mejía-García; E. Díaz-Valdés; G. Contreras-Puente; J. L. López-López; Milan Jergel; A. Morales

2004-01-01

23

Influence of ion irradiated SrTiO/sub 3/ on the properties of thin film oxide superconductors  

SciTech Connect

The quality of high temperature superconducting thin films is dependent on the structure of the substrate used. The present work examines the effects of radiation damaged SrTiO/sub 3/ substrates on the properties of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ thin film superconductors. Prior to film deposition, single crystal SrTiO/sub 3/ substrates were cooled to 77 K and irradiated with 400 keV Ne ions to doses of 1 /times/ 10/sup 15/ and 1 /times/ 10/sup 16/ ions/cm/sup 2/. Following deposition the film/substrate couples were annealed in ''wet'' oxygen at either 850 or 900/degree/C. Films on substrates irradiated at high doses showed an increase in transition width from 2 to 8 degrees and lowered transition temperature from 92 to 65 K relative to films on low dose and unirradiated substrates. These differences are discussed in terms of results obtained from high energy and Rutherford backscattering (RBS) and channeling experiments, scanning electron microscopy (SEM) observations and x-ray diffraction data (XRD).

Bordes, N.; Cohen, M.; Nastasi, M.; Rollett, A.D.; Maggiore, C.J.

1989-01-01

24

Preparation of Y-Ba-Cu oxide superconductor thin films using pulsed laser evaporation from high T\\/sub c\\/ bulk material  

Microsoft Academic Search

We report the first successful preparation of thin films of Y-Ba-Cu-O superconductors using pulsed excimer laser evaporation of a single bulk material target in vacuum. Rutherford backscattering spectrometry showed the composition of these films to be close to that of the bulk material. Growth rates were typically 0.1 nm per laser shot. After an annealing treatment in oxygen the films

D. Dijkkamp; T. Venkatesan; X. D. Wu; S. A. Shaheen; N. Jisrawi; Y. H. Min-Lee; W. L. McLean; M. Croft

1987-01-01

25

Preparation of Y-Ba-Cu oxide superconductor thin films using pulsed laser evaporation from high T(c) bulk material  

Microsoft Academic Search

The first successful preparation of thin films of Y-Ba-Cu-O superconductors using pulsed excimer laser evaporation of a single bulk material target in vacuum is reported. Rutherford backscattering spectrometry showed the composition of these films to be close to that of the bulk material. Growth rates were typically 0.1 nm per laser shot. After an annealing treatment in oxygen the films

D. Dijkkamp; T. Venkatesan; X. D. Wu; S. A. Shaheen; N. Jisrawi; Y. H. Min-Lee; W. L. McLean; M. Croft

1987-01-01

26

Atomic layer deposition of amorphous niobium carbide-based thin film superconductors.  

SciTech Connect

Niobium carbide thin films were synthesized by atomic layer deposition (ALD) using trimethylaluminum (TMA), NbF{sub 5}, and NbCl{sub 5} precursors. In situ quartz crystal microbalance (QCM) measurements performed at 200 and 290 C revealed controlled, linear deposition with a high growth rate of 5.7 and 4.5 {angstrom}/cycle, respectively. The chemical composition, growth rate, structure, and electronic properties of the films were studied over the deposition temperature range 125-350 C. Varying amounts of impurities, including amorphous carbon (a-C), AlF{sub 3}, NbF{sub x}, and NbCl{sub x}, were found in all samples. A strong growth temperature dependence of film composition, growth rate, and room temperature DC resistivity was observed. Increasing film density, decreasing total impurity concentration, and decreasing resistivity were observed as a function of increasing deposition temperature for films grown with either NbF{sub 5} or NbCl{sub 5}. Superconducting quantum interference device (SQUID) magnetometry measurements down to 1.2 K revealed a superconducting transition at T{sub c} = 1.8 K in a 75 nm thick film grown at 350 C with TMA and NbF{sub 5}. The superconducting critical temperature could be increased up to 3.8 K with additional use of NH{sub 3} during ALD film growth.

Klug, J. A.; Prolier, T.; Elam, J. W.; Becker, N. G.; Pellin, M. J. (Energy Systems); ( HEP); ( MSD); (Illinois Inst. Tech.)

2011-01-01

27

atomic layer deposition of amorphous niobium carbide-based thin film superconductors.  

SciTech Connect

Niobium carbide thin films were synthesized by atomic layer deposition (ALD) using trimethylaluminum (TMA), NbF{sub 5}, and NbCl{sub 5} precursors. In situ quartz crystal microbalance (QCM) measurements performed at 200 and 290 C revealed controlled, linear deposition with a high growth rate of 5.7 and 4.5 {angstrom}/cycle, respectively. The chemical composition, growth rate, structure, and electronic properties of the films were studied over the deposition temperature range 125-350 C. Varying amounts of impurities, including amorphous carbon (a-C), AlF{sub 3}, NbF{sub x}, and NbCl{sub x}, were found in all samples. A strong growth temperature dependence of film composition, growth rate, and room temperature DC resistivity was observed. Increasing film density, decreasing total impurity concentration, and decreasing resistivity were observed as a function of increasing deposition temperature for films grown with either NbF{sub 5} or NbCl{sub 5}. Superconducting quantum interference device (SQUID) magnetometry measurements down to 1.2 K revealed a superconducting transition at T{sub c} = 1.8 K in a 75 nm thick film grown at 350 C with TMA and NbF{sub 5}. The superconducting critical temperature could be increased up to 3.8 K with additional use of NH{sub 3} during ALD film growth.

Prolier, T.; Klug, J. A.; Elam, J. W.; Claus, H.; Becker, N. G.; Pellin, M. J. (Materials Science Division)

2011-01-01

28

Raman scattering study of phonons in Bi-based superconductor thin films  

NASA Astrophysics Data System (ADS)

Raman spectra were obtained from samples of Bi Pb Sr Ca Cu O (BPSCCO) thin films after varying several growth parameters, such as covering material, annealing time (tR), annealing temperature (TR), and nominal lead content (x). Thin films with the nominal composition Bi1.4PbxSr2Ca2Cu3O? were grown on MgO substrates by a spray pyrolysis technique, followed by a solid state reaction. The results of Raman scattering measurements at room temperature show a series of vibrational optical modes within the range 300 900 cm-1. The assignment of these modes was made by involving mainly the 2212 and 2223 phases and was confirmed by both X-ray diffraction and resistance in dependence of the temperature (R T) measurements as well.

Mejía-García, C.; Díaz-Valdés, E.; Contreras-Puente, G.; López-López, J. L.; Jergel, M.; Morales, A.

2004-11-01

29

Raman scattering study of phonons in Bi-based superconductor thin films  

NASA Astrophysics Data System (ADS)

Raman spectra were obtained from samples of Bi-Pb-Sr-Ca-Cu-O (BPSCCO) thin films varying several growth parameters such as covering material, annealing time tR, annealing temperature TR and lead content x. Thin films with nominal composition of Bi1.4PbxSr2Ca2Cu3Od were grown on MgO substrates by spray pyrolysis technique followed by a solid state reaction. The results of Raman scattering at room temperature show a series of vibrational optical modes within the range of 300 up to 900 cm-1. The assignment of these modes was made by involving mainly the 2212 and 2223 phases confirmed also by both, X-ray diffraction and R-T measurements as well.

Mejía-García, Concepción; López-López, José Luis; Díaz-Valdés, Elvia; Contreras-Puente, Gerardo; Jergel, Milan

2004-03-01

30

Application of a spatial composition spread approach to the preparation of thin film cuprate superconductor libraries  

NASA Astrophysics Data System (ADS)

A spatial composition spread approach was developed to explore the Bi 2Sr2Y(1--x )CaxOy (0?x?1)(Bi-2212) and the La(2--x)Sr xCuO4 (0?x?0.18)(La-214) cuprate systems. Using targets produced on-site, a series of depositions (approximately 75) were made by DC and RF magnetron sputtering to produce films with a linearly varying composition. Various conditions were tested to produce the best quality Bi-2212 and La-214 films. High pressure depositions with a -20 V substrate bias effectively reduced an oxygen resputtering problem, but the resultant film was still rich in Bi and deficient in both Sr and Ca. 'These deficiencies led to phase impurity in the crystallized films. A comprehensive study on the deposition conditions highlighted a problem with using multi-element targets containing both Bi and Ca. Using a modified thermalized gas model, we defined a parameter called the Throughput, to help quantify the experimental trends. Both the Throughput calculations and the experimental data suggested that low pressure depositions would increase both the Sr and Ca concentrations. Low pressure depositions increased the Sr and Ca concentrations in the film. However, even with a substrate bias the film composition was not uniform due to resputtering. The variation of the film composition, caused by the resputtering, again results in a multi-phase film. From the Throughput calculations, the La-214 system was determined to be a more favorable system to study. Initial results from the La-214 system demonstrated the ability to produce a uniform phase across the entire deposition range, and this has been confirmed in recent measurements by another member (Mehran Saadat) of the group. Overall many of the problems associated with depositing cuprate thin-films were overcome, and a simple, yet effective model, was developed to determine which multi-element targets would be suitable for our method.

Sanderson, Robert James

31

High-energy helium backscattering for the compositional analysis of thin-film oxide-superconductors  

SciTech Connect

Recent experiments have demonstrated that the broad elastic-scattering resonance for 8.8 MeV helium bombardment of oxygen can be exploited to measure the oxygen content of YBaCuO thin films. A potential difficulty with such measurements is distortion of the backscattering spectrum due to resonant scattering from the substrate elements, which could prevent the accurate integration of peak areas. We have measured the elastic scattering cross sections for Sr and Ti, relative to Gd, with He ions in the energy range of 2.2--8.8 MeV, and a scattering angle of 166/degree/. The results verify that resonant scattering from the substrate does not interfere with the high-energy compositional analysis of YBaCuO films deposited on SrTiO/sub 3/. Scattering cross sections for Ca, measured relative to Ba, have also been determined for application to the analysis of BiSrCaCuO and TlCaBaCuO films. Because of resonant scattering from Ca at beam energies above 6 MeV, two backscattering measurements are required for these materials: one at 8.8 MeV to determine the O content, and one at or below 6 MeV to determine the Ca content. Anticipating a more general applicability of this technique to the analysis of metal-oxide films, data are also presented for a number of elements, as an empirical guideline, which give the beam energies above which scattering cross sections deviate from their Rutherford values, and must be determined experimentally. 10 refs., 6 figs., 4 tabs.

Hubbard, K.M.; Martin, J.A.; Muenchausen, R.E.; Tesmer, J.R.; Nastasi, M.

1989-01-01

32

High-Frequency Electron Dynamics in Thin Film Superconductors and Applications to Fast, Sensitive Thz Detectors  

NASA Astrophysics Data System (ADS)

This thesis is an experimental study of the dynamics and noise processes in diffusion and phonon-cooled superconducting hot-electron bolometer mixers which will serve as ultra-low noise detectors in THz heterodyne receivers. The conversion efficiency and output noise of devices of varying lengths were measured with rf frequencies between 8 and 40 GHz. The devices studied consist of 100 A thin film Nb bridges connected to thick (1000 A), high conductivity normal metal (Au) leads. The lengths of the devices studied range from 0.08 ?m to 3 ?m. For devices longer than the electron-phonon interaction length Le-ph?/sqrt[D?e-ph], with D the diffusion constant and ?e-ph-1 the electron-phonon interaction rate, the hot-electrons are cooled dominantly by the electron-phonon interaction, which in Nb is too slow for practical applications. If the device length is less than ? Le-ph/ (?1/ ?m at 4.2 K), then out-diffusion of heat into the high conductivity leads dominates the cooling process. In this limit, the intermediate frequency (IF) bandwidth is found to vary as L-2, with L the bridge length, as expected for diffusion cooling. The shortest device has an IF bandwidth greater than 6 GHz, the largest reported for a low-Tc superconducting bolometric mixer. The component of the output noise not due to Johnson noise decreases with frequency in the same manner as the conversion efficiency, consistent with a model based on thermal fluctuations. The noise bandwidth is 1.4-9.4 times larger than the gain bandwidth, and the mixer noise is low, ranging from 120-530 K (double side-band). The crossover from phonon dominated to diffusion dominated behavior is also demonstrated using noise thermometry measurements in the normal state. Scalar measurements of the device differential impedance in the intermediate state agree with a theoretical model which takes into account the thermal and electrical dynamics.

Burke, Peter John

33

Preparation of Y-Ba-Cu oxide superconductor thin films using pulsed laser evaporation from high T/sub c/ bulk material  

SciTech Connect

We report the first successful preparation of thin films of Y-Ba-Cu-O superconductors using pulsed excimer laser evaporation of a single bulk material target in vacuum. Rutherford backscattering spectrometry showed the composition of these films to be close to that of the bulk material. Growth rates were typically 0.1 nm per laser shot. After an annealing treatment in oxygen the films exhibited superconductivity with an onset at 95 K and zero resistance at 85 and 75 K on SrTiO/sub 3/ and Al/sub 2/O/sub 3/ substrates, respectively. This new deposition method is relatively simple, very versatile, and does not require the use of ultrahigh vacuum techniques.

Dijkkamp, D.; Venkatesan, T.; Wu, X.D.; Shaheen, S.A.; Jisrawi, N.; Min-Lee, Y.H.; McLean, W.L.; Croft, M.

1987-08-24

34

Thin-film Bi-Sr-Ca-Cu-O high-temperature superconductors using pulsed laser evaporation from sintered disks  

SciTech Connect

Films of the high-temperature superconductor in the Bi-Sr-Ca-Cu-O system were deposited by pulsed laser evaporation from a ceramic disk. Films deposited onto (100) MgO show x-ray diffraction patterns characteristic of c-axis textured Bi/sub 2/(Sr,Ca,Bi)/sub 3/Cu/sub 2/O/sub x/ phase following annealing for 10 min at 850 /sup 0/C in 20% O/sub 2/-80% N/sub 2/. These textured films have zero resistance at 78 K and show resistance drops near 110 K. The effects of the annealing environment on the electrical and structural properties are presented.

Guarnieri, C.R.; Roy, R.A.; Saenger, K.L.; Shivashankar, S.A.; Yee, D.S.; Cuomo, J.J.

1988-08-08

35

Self-ordering of random intercalates in thin films of cuprate superconductors: Growth model and x-ray diffraction diagnosis  

SciTech Connect

We propose a simple model for the nucleation of random intercalates during the growth of high-temperature superconductor (HTSC) films by pulsed laser deposition (PLD). The model predicts a very particular spatial distribution of defects: a Markovian-like sequence of displacements along the growth direction (c axis), as well as a two-component in-plane correlation function, characteristic of self-organized intercalates. A model for x-ray diffraction (XRD) on such structures is also developed and accounts for both c-axis and in-plane anomalies observed in XRD experiments. The method presented in this work constitutes a useful characterization tool in the optimization of deposition parameters for the growth of HTSC films.

Ariosa, D.; Cancellieri, C.; Pavuna, D. [Laboratory of X-ray, EPFL SB-IPMC-LPRX, CH-1015 Lausanne (Switzerland); Lin, P. H. [Laboratory of X-ray, EPFL SB-IPMC-LPRX, CH-1015 Lausanne (Switzerland); Department of Engineering and System Science, National Tsing Hua University, TW-30013, Taiwan (China); Academia Sinica, Institute of Physics, TW-11529, Taiwan (China)

2007-05-01

36

Thin Film Interference Model  

NSDL National Science Digital Library

The Thin Film Interference model investigates reflection and transmission of light through a thin film. The user can change the thickness and index of refraction of the thin film as well as the incident light wavelength. The Thin Film Interference Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_ThinFilm.jar file will run the program if Java is installed.

Duffy, Andrew

2010-04-25

37

Synthesis and characterization of alkaline-earth-metal. beta. -diketonate complexes used as precursors for chemical vapor deposition of thin-film superconductors  

SciTech Connect

Several of the {beta}-diketonate metal complexes used for metal organic chemical vapor deposition (MOCVD) of thin-film superconductors have been characterized by thermogravimetric analysis, mass spectrometry, and gas chromatography/mass spectrometry. The volatility of the alkaline-earth-metal chelates has been studied, and it has been determined that one reason the alkaline-earth-metal chelates are less volatile than other metal {beta}-diketonates is that they exist as oligomers. For example, one barium {beta}-diketonate chelate consists of a cluster of five metal ions bridged by {beta}-diketonate carbonyl oxygens and water molecules. It has also been found that the addition of uncomplexed (protonated) {beta}-keto enolate ligand to the carrier gas stream greatly improves the gas chromatographic behavior of these alkaline-earth-metal chelates, probably owing to adduct formation accompanying the dissociation of the oligomers. The results of these studies, as well as the implications for using these chelates together with auxiliary ligands for MOCVD, will be discussed. 3 tables, 5 figs., 26 refs.

Turnipseed, S.B.; Barkley, R.M.; Sievers, R.E. (Univ. of Colorado, Boulder (USA))

1991-03-01

38

Equilibrium Microstructure of Epitaxial Thin Films  

Microsoft Academic Search

The research presented in this thesis addresses the problem of the equilibrium structure of epitaxial thin films, particularly in regard to domain formation. Many examples of structural domain formation exist in the literature of which high T_{c} superconductors and ferroelectric materials are but two examples. The understanding and control of domain formation is of vital importance in many cases due

Scott Allen Little

1993-01-01

39

Transport properties at the insulator-superconductor phase boundary of La2-xSrxCuO4 thin films  

NASA Astrophysics Data System (ADS)

The longitudinal resistivity and the transverse Hall resistivity of La1.94Sr0.06CuO4 and La1.97Sr0.03CuO4 epitaxial thin films are investigated. The zero-field resistivity ?/(T) of La1.94Sr0.06CuO4 shows a minimum at 80 K and a resistive midpoint of the superconducting transition at Tcmid~7.5 K. A magnetic field of 8 T suppresses the superconducting state and induces a semiconducting normal state with ?/(T) increasing with decreasing temperature. The resistivity of La1.97Sr0.03CuO4 has a minimum at 100 K and no superconducting transition is observed down to 1.5 K. The semiconducting low-temperature behaviour can be described by Shlovskii-Efros hopping, while the metallic-like regime corresponds to 1D quantum transport of charge stripes. The field dependence of the Hall resistivity ?xy/(B) has an opposite behaviour for the two doping levels: the ?xy/(B) slope of La1.94Sr0.06CuO4 decreases with decreasing temperature, while it increases in the case of La1.97Sr0.03CuO4. Within the superconducting transition regime of La1.94Sr0.06CuO4 (below 15 K) we observe a sign inversion of ?xy/(B) in the limit of weak magnetic fields.

Wagner, P.; Ruan, K.-Q.; Gordon, I.; Vanacken, J.; Moshchalkov, V. V.; Bruynseraede, Y.

2001-07-01

40

Optical thin film devices  

NASA Astrophysics Data System (ADS)

Thin film devices are applied to almost all modern scientific instruments, and these devices, especially optical thin film devices, play an essential role in the performances of the instruments, therefore, they are attracting more and more attention. Now there are numerous kinds of thin film devices and their applications are very diversified. The 300-page book, 'Thin Film Device and Applications,' by Prof. K. L. Chopra gives some general ideas, and my paper also outlines the designs, fabrication, and applications of some optical thin film devices made in my laboratory. Optical thin film devices have been greatly developed in the recent decades. Prof. A. Thelan has given a number of papers on the theory and techniques, Prof. H. A. Macleod's book, 'Thin Film Optical Filters,' has concisely concluded the important concepts of optical thin film devices, and Prof. J. A. Dobrowobski has proposed many successful designs for optical thin film devices. Recently, fully-automatic plants make it easier to produce thin film devices with various spectrum requirements, and some companies, such as Balzers, Leybold AG, Satis Vacuum AG, etc., have manufactured such kinds of coating plants for research or mass-production, and the successful example is the production of multilayer antireflection coatings with high stability and reproducibility. Therefore, it could be said that the design of optical thin film devices and coating plants is quite mature. However, we cannot expect that every problem has been solved, the R&D work still continues, the competition still continues, and new design concepts, new techniques, and new film materials are continually developed. Meanwhile, the high-price of fully-automatic coating plants makes unpopular, and automatic design of coating stacks is only the technique for optimizing the manual design according to the physical concepts and experience, in addition, not only the optical system, but also working environment should be taken into account when designing optical thin film devices. Therefore, chemical and mechanical, as well as optical properties of thin films and optical system, should be known. Following is the outline of design method and applications of optical thin film devices according to the classification of our factory, Shanghai Optical Instrument Factory.

Mao, Shuzheng

1991-11-01

41

Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures  

SciTech Connect

Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 [Angstrom]), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 [Angstrom] of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films.

Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M. (Argonne National Lab., IL (United States)); Schultz, J.A. (Ionwerks, Inc., Houston, TX (United States)); Schmidt, H.K. (Schmidt Instruments, Inc., Houston, TX (United States)); Chang, R.P.H. (Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science)

1992-01-01

42

Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures  

SciTech Connect

Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 {Angstrom}), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 {Angstrom} of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films.

Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M. [Argonne National Lab., IL (United States); Schultz, J.A. [Ionwerks, Inc., Houston, TX (United States); Schmidt, H.K. [Schmidt Instruments, Inc., Houston, TX (United States); Chang, R.P.H. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science

1992-11-01

43

Thin film growth by pulsed laser deposition and properties of 122-type iron-based superconductor AE(Fe1-xCox)2As2 (AE=alkaline earth)  

NASA Astrophysics Data System (ADS)

This paper reports comprehensive results on thin film growth of 122-type iron-pnictide superconductors, AE(Fe1-xCox)2As2 (AE= Ca, Sr, and Ba, AEFe2As2:Co) by a pulsed laser deposition method using a neodymium-doped yttrium aluminum garnet laser as an excitation source. The most critical parameter to produce the SrFe2As2:Co and BaFe2As2:Co phases is the substrate temperature (Ts). It is difficult to produce highly pure CaFe2As2:Co phase thin film at any Ts. For BaFe2As2:Co epitaxial films, controlling Ts at 800-850?°C and growth rate to 2.8-3.3 Å s-1 produced high-quality films with good crystallinity, flat surfaces, and high critical current densities > 1 MA cm -2, which were obtained for film thicknesses from 100 to 500 nm. The doping concentration x was optimized for Ba(Fe1-xCox)2As2 epitaxial films, leading to the highest critical temperature of 25.5 K in the epitaxial films with the nominal x = 0.075.

Katase, Takayoshi; Hiramatsu, Hidenori; Kamiya, Toshio; Hosono, Hideo

2012-08-01

44

Studies of solution deposited cerium oxide thin films on textured Ni-alloy substrates for YBCO superconductor  

SciTech Connect

Cerium oxide (CeO{sub 2}) buffer layers play an important role for the development of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) based superconducting tapes using the rolling assisted biaxially textured substrates (RABiTS) approach. The chemical solution deposition (CSD) approach has been used to grow epitaxial CeO{sub 2} films on textured Ni-3 at.% W alloy substrates with various starting precursors of ceria. Precursors such as cerium acetate, cerium acetylacetonate, cerium 2-ethylhexanoate, cerium nitrate, and cerium trifluoroacetate were prepared in suitable solvents. The optimum growth conditions for these cerium precursors were Ar-4% H{sub 2} gas processing atmosphere, solution concentration levels of 0.2-0.5 M, a dwell time of 15 min, and a process temperature range of 1050-1150 deg. C. X-ray diffraction, AFM, SEM, and optical microscopy were used to characterize the CeO{sub 2} films. Highly textured CeO{sub 2} layers were obtained on Ni-W substrates with both cerium acetate and cerium acetylacetonate as starting precursors. YBCO films with a J {sub c} of 1.5 MA/cm{sup 2} were obtained on cerium acetylacetonate-based CeO{sub 2} films with sputtered YSZ and CeO{sub 2} cap layers.

Stewart, E. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Bhuiyan, M.S. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Sathyamurthy, S. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Paranthaman, M. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States)]. E-mail: paranthamanm@ornl.gov

2006-06-15

45

Thin film hydrogen sensor  

DOEpatents

A thin film hydrogen sensor includes a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end. 5 figs.

Cheng, Y.T.; Poli, A.A.; Meltser, M.A.

1999-03-23

46

Electroluminescent Thin Film Research.  

National Technical Information Service (NTIS)

Through modifications in the source design and vacuum deposition procedures leading to increased activator concentration, improved thin film, electroluminescent (EL) phosphor materials were made having outstanding characteristics for display applications....

E. J. Soxman

1966-01-01

47

Thin film solar cells  

SciTech Connect

Written for graduate students and R and D scientists and engineers, this text provides a lucid treatment of many facets of materials, technologies, and solid-state physics of thin film solar cell devices. The various types of homo-, hetero-, barrier, and liquid junction solar cells involving amorphous, polycrystalline, and epitaxial semiconductor thin films are all covered. The volume details the basic solid-state physics of junction devices and describes thin film materials and associated preparation, measurement, and analysis techniques, as well as device technology. The authors present a critical comparative analysis of the performance of various types of thin film solar cells in order to focus on the present status of the field and to project future developments.

Chopra, K.L.; Das, S.R.

1983-01-01

48

Simulated Thin-Film Growth and Imaging  

NASA Astrophysics Data System (ADS)

Thin-films have become the cornerstone of the electronics, telecommunications, and broadband markets. A list of potential products includes: computer boards and chips, satellites, cell phones, fuel cells, superconductors, flat panel displays, optical waveguides, building and automotive windows, food and beverage plastic containers, metal foils, pipe plating, vision ware, manufacturing equipment and turbine engines. For all of these reasons a basic understanding of the physical processes involved in both growing and imaging thin-films can provide a wonderful research project for advanced undergraduate and first-year graduate students. After producing rudimentary two- and three-dimensional thin-film models incorporating ballsitic deposition and nearest neighbor Coulomb-type interactions, the QM tunneling equations are used to produce simulated scanning tunneling microscope (SSTM) images of the films. A discussion of computational platforms, languages, and software packages that may be used to accomplish similar results is also given.

Schillaci, Michael

2001-06-01

49

Thin film tritium dosimetry  

DOEpatents

The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

Moran, Paul R. (Madison, WI)

1976-01-01

50

Exploring Materials: Thin Films  

NSDL National Science Digital Library

In this activity, learners create a colorful bookmark using a super thin layer of nail polish on water. Learners discover that a thin film creates iridescent, rainbow colors. This is a very fun and engaging activity for learners, and a great way to talk about how nanoscale structures often affect a materials' properties. SAFETY: Do this activity in a well-ventilated area.

Network, Nanoscale I.; Sciencenter

2010-01-01

51

Thin Film Microcircuit Interconnections.  

National Technical Information Service (NTIS)

Process specifications for the deposition of all the thin films have been finalized. The technique for fabricating tantalum-aluminum films has been changed. AC impedance measurements at 200 MHz indicate that this technique is not as good as DC measurement...

H. M. Greenhouse R. T. Galla T. H. Yaffe W. W. Richardson

1966-01-01

52

Critical state in a circular two-dimensional superconductor and magnetization of thin Nd1.85Ce0.15CuO4-? and YBa2Cu3O7-? films in a transverse field  

NASA Astrophysics Data System (ADS)

Precise measurements of the magnetization of circular epitaxial Nd1.85Ce0.15CuO4-? and YBa2Cu3O7-? films in a transverse magnetic field are performed and analyzed within the framework of the recently presented critical state model (CSM) in the two-dimensional superconductor. Restrictions on the reliability of the model are considered. It has been found that the original CSM, based on Bean's limitation on the critical current density Jc=const, describes well the temperature and field dependences of the film magnetization in a low field (until the full disappearance of the flux-free region in the film) under the condition B*>>?0dJcln(?Rd /?), where B* is the characteristic field of the critical current drop in a strong field, ? is the penetration depth, d is the thickness, and R is the radius of the film, respectively. In the strong field an exponential or power suppression of the critical current is observed and the model under question is extended to this region. The problem of a lower critical field related to thin films is also discussed. The paramagnetic response demonstrated by all our films in field-cooled measurements, which has much in common with the Wohlleben effect, was investigated and the conclusion was drawn that this artifact is caused by the temperature-dependent stray field of the magnetometer parts.

Kuznetsov, A. V.; Ivanov, A. A.; Eremenko, D. V.; Trofimov, V. N.

1995-10-01

53

Heterogeneity in Polymer Thin Films  

NASA Astrophysics Data System (ADS)

In the last two decades very extensive studies have been performed on polymer thin films to reveal very interesting but unusual properties. One of the most interesting findings is the decrease in glass transition temperature Tg with film thickness in polystyrene (PS) thin film supported on Si substrate. Another interesting finding is apparent negative thermal expansivity in glassy state for thin films below ~25 nm. In order to understand the unusual properties of polymer thin films we have studied temperature dependence of thickness of polystyrene thin films by means of X-ray and neutron reflectivity. In addition, we also studied dynamics of PS thin films using inelastic neutron scattering. In the presentation we will discuss the results from viewpoints of heterogeneity of polymer thin films. Finally we did neutron reflectivity measurements on a 5-layer thin film, consisting of alternatively stacked d-PS and h-PS layers to see the distribution of glass transition temperature and thermal expansivity directly.

Kanaya, Toshiji; Inoue, Rintaro; Nishida, Koji

2011-07-01

54

Thin film photovoltaic device  

DOEpatents

A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

Catalano, Anthony W. (Wilmington, DE); Bhushan, Manjul (Wilmington, DE)

1982-01-01

55

Thin Film Solar Cell Workshop.  

National Technical Information Service (NTIS)

A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and...

J. Armstrong F. Jeffrey

1993-01-01

56

Thin-film optical initiator  

DOEpatents

A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.

Erickson, Kenneth L. (Albuquerque, NM)

2001-01-01

57

Magnetism of nanostructured thin films  

Microsoft Academic Search

Nanostructured magnetic materials have unique properties that are different from bulk materials. They are of great scientific interest, as provide many potential applications. This thesis presents the structural and magnetic properties of FePt thin films and FePt-based nanocomposite thin films. FePt thin films were deposited by magnetron sputtering. By annealing the as-deposited films, high-anisotropy L10 FePt films were obtained. The

Chunping Luo

2000-01-01

58

Thin film photovoltaic cell  

DOEpatents

A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

Meakin, John D. (Newark, DE); Bragagnolo, Julio (Newark, DE)

1982-01-01

59

Thin Film Microcircuit Interconnections.  

National Technical Information Service (NTIS)

An evaluation was made of thin film interfacial interconnections and insulating crossovers. The interconnections were subjected to -55C, 125C, and 200C storage for 1000 hrs. 100 thermal cycles from -65C to 125C; and an accelerated aging at 240C (Interfaci...

H. M. Greenhouse R. T. Galla T. H. Yaffe W. W. Richardson W. C. Vergara

1967-01-01

60

Thin film ellipsometry metrology  

NASA Astrophysics Data System (ADS)

A wide variety of commercial ellipsometers are available in the market today. They all measure the change in the state of polarization of light on reflection, but the measurement techniques adopted vary from instrument to instrument. Further, the models used to evaluate the thickness and refractive index of the oxide film during analysis of measurement data vary in complexity. The two main techniques of measurement are single wavelength ellipsometry and spectroscopic ellipsometry. The NIST Standard Reference Materials available today are based on conventional single wavelength ellipsometry. We discuss the challenges encountered in providing reference materials by using spectroscopic ellipsometry. First, the limits of conventional single wavelength ellipsometric determination of film thickness are investigated and then possible new technologies are explored. We present a discussion comparing the different types of instruments available and how their unique designs affect the accuracy of thickness determinations. Manufacturing, and accurate determination, of thickness of films this thin (<10 nm) is a challenging task. Results from independent ellipsometric measurements on two different types of instruments are compared for the case of ultra thin thermally grown silicon dioxide films on silicon crystal substrates. Stability curves for the thickness of thin dielectric films over a period of two years are also presented.

Durgapal, Prabha; Ehrstein, James R.; Nguyen, Nhan V.

1998-11-01

61

Biomimetic thin film deposition  

SciTech Connect

Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

1995-09-01

62

Advanced thin film thermocouples  

NASA Astrophysics Data System (ADS)

The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.

Kreider, K. G.; Semancik, S.; Olson, C.

1984-10-01

63

Thin film resonator technology.  

PubMed

Advances in wireless systems have placed increased demands on high performance frequency control devices for operation into the microwave range. With spectrum crowding, high bandwidth requirements, miniaturization, and low cost requirements as a background, the thin film resonator technology has evolved into the mainstream of applications. This technology has been under development for over 40 years in one form or another, but it required significant advances in integrated circuit processing to reach microwave frequencies and practical manufacturing for high-volume applications. This paper will survey the development of the thin film resonator technology and describe the core elements that give rise to resonators and filters for today's high performance wireless applications. PMID:16048174

Lakin, Kenneth M

2005-05-01

64

Thin film composite electrolyte  

DOEpatents

The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.

Schucker, Robert C. (The Woodlands, TX)

2007-08-14

65

Thin film photonic crystals  

Microsoft Academic Search

Large area thin film photonic crystals consisting either of closely packed PMMA balls or their SnS2 replicas have been synthesized and tested. The photonic bandgap (PBG) of these structures demonstrates a tendency towards omnidirectionality and a subsequent increase of the refractive index contrast (RIC) in the inverted opal structure. In particular, the bandgap width in SnS2 replica exceeds that of

Sergei G Romanov; Torsten Maka; Clivia M Sotomayor Torres; Manfred Müller; Rudolf Zentel

2001-01-01

66

Superconducting thin films. (Latest citations from the EI Compendex*plus database). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, fabrication, structures, and properties of superconducting thin films used in microelectronics and optoelectronics. References discuss high temperature superconductors, oxide superconductors, superconducting transition temperatures, critical current density, yttrium barium copper oxide thin films, and yttrium stabilized substrates. Superconducting devices, filters, resonators, and circuits are also reviewed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1997-12-01

67

Polycrystalline thin film photovoltaic technology  

SciTech Connect

Low-cost, high-efficiency thin-film modules are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. In this paper we review the significant technical progress made in the following thin films: copper indium diselenide, cadmium telluride, and polycrystalline thin silicon films. Also, the recent US DOE/SERI initiative to commercialize these emerging technologies is discussed. 6 refs., 9 figs.

Ullal, H.S.; Zweibel, K.; Mitchell, R.L.; Noufi, R.

1991-03-01

68

Equilibrium Microstructure of Epitaxial Thin Films  

NASA Astrophysics Data System (ADS)

The research presented in this thesis addresses the problem of the equilibrium structure of epitaxial thin films, particularly in regard to domain formation. Many examples of structural domain formation exist in the literature of which high T_{c} superconductors and ferroelectric materials are but two examples. The understanding and control of domain formation is of vital importance in many cases due to its profound impact on the desired physical properties of these films. The film material is presumed to undergo a structural phase transition in the bulk. Specifically, the two-dimensional square-rectangular phase transition will be studied. Theoretical models of various epitaxial effects on thin films are constructed. The monolayer film model is developed as an extension of the Frenkel-Kontorova model, in which the film is modeled by a chain of atoms connected by springs interacting with a sinusoidal potential representing the substrate. The ordinary Hooke's law springs are replaced with non-linear springs having the Devonshire triple well form in order to generate three competing lengths for the unit cells of the film analogous to the three distinct bulk film lattice constants. The phase diagram of this model as a function of misfit and temperature is generated and found to contain many different equilibrium structures, some of which are surprisingly complex. To include film height effects and the possible relaxation of the substrate due to the presence of the film, the one dimensional elasticity calculation of Roitburd is generalized to two dimensions and a wider range of misfit between the film and the substrate. Two competing mechanisms of epitaxial strain relief, misfit dislocations and domain formation, are considered and the phase diagram of equilibrium structures as a function of misfit, film height and temperature is constructed. Incommensurate domain structures are studied and found to be stable for a limited region of the phase diagram. Many applications to experimental systems are discussed.

Little, Scott Allen

69

Multilayer Ferromagnetic Thin Films.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. Requires signed TDF. In recent years artificial multilayer thin films have attracted considerable interest, since it is hoped that these new materials will exhibit novel and interesting as well as useful electrical, magnetic and mechanical properties. For example, multilayer ferromagnetic thin films with perpendicular anisotropy are currently of greatest interest as vertical magnetic recording media. In addition, for ultrathin layers (i.e. several atomic layers), new materials with new structural and magnetic properties are expected. In this study, ultrathin multilayer ferromagnetic thin films have been investigated. They have been fabricated by a dual sputtering system with revolving substrate. This apparatus provided the flexibility necessary to produce samples with individual layer thicknesses ranging from 0.05 nm to several nm. The multilayers were prepared by sequential deposition if ferromagnetic cobalt and non-magnetic Al, Cr, Zr or W films onto different types of substrates. The experimental and analytical techniques used to investigate the structural characteristics of these multilayer systems included Rutherford Backscattering, Transmission Electron Microscopy, and large and small X -ray diffraction. The magnetic properties have been measured, analyzed and correlated with the structural properties. For example, the reduced symmetry, surface anisotropy, and strains developed at the interfaces strongly affect the magnetic properties of the samples. An interesting phenomenon observed in these films is the formation of amorphous phases when the layers are reduced to a few atomic distances in thickness. This is the case for the Co/W and Co/Zr systems, where the multilayer is amorphous when the layers are thin, and then changes to a polycrystalline form when the layers become thicker. The magnetic measurements for all systems show that the magnetic properties are strongly dependent on the cobalt layer thickness. An interesting result for Co/W and CO/Cr multilayers is the development of perpendicular anisotropy with decreasing layer thickness (in both systems, the magnetization in the perpendicular direction becomes easier as the layer thickness and the periodicity of the multilayer decreases).

Babkair, Saeed Salem

70

Probing thin-film YBa2Cu307-delta superconductors by second-harmonic generation using femtosecond laser pulses. Technical report  

SciTech Connect

High temperature superconducting thin films of YBa2Cu307-Delta are examined by measuring the second-harmonic-generated (SHG) signal from an incident 60 fs laser pulse of 2.0 eV (620 nm) in air at room temperature. As oxygen stoichiometry is varied ( 0. 00 < Delta < 0. 50 ), large changes in the SHG intensity are observed. The oxygen content of the films is independently determined by measuring (i) the c-axis lattice parameter derived from x-ray diffraction and (ii) the stoichiometry of the films determined by elastic backscattering spectrometry. We report a negative correlation of the SHG intensity with the c-axis parameter indicating that a known compression of the c-axis leads to a larger SHG signal. An additional experiment in which the SHG intensity is monitored as a function of temperature (300 K to 20 K) in vacuum is performed. A gradual increase of - 50 % in the SHG intensity is observed as the temperature is lowered which can also be correlated to a decrease in the length of the c-axis. Other experiments including rotation anisotropy and polarization of the incident and analyzer beams are also discussed.

Rice, J.K.; McCauley, S.W.; Baronavski, A.P.; Horwitz, J.S.; Chrisey, D.B.

1992-05-29

71

Thin-film metal coated insulation barrier in a Josephson tunnel junction. [Patent application  

DOEpatents

A highly stable, durable, and reproducible Josephson tunnel junction consists of a thin-film electrode of a hard superconductor, a thin oxide insulation layer over the electrode constituting a Josephson tunnel junction barrier, a thin-film layer of stabilizing metal over the barrier, and a second thin-film hard superconductive electrode over the stabilizing film. The thin stabilizing metal film is made only thick enough to limit penetration of the electrode material through the insulation layer so as to prevent a superconductive short.

Hawkins, G.A.; Clarke, J.

1975-10-31

72

Thin film hydrogen sensor  

DOEpatents

A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed.

Lauf, Robert J. (Oak Ridge, TN); Hoffheins, Barbara S. (Knoxville, TN); Fleming, Pamela H. (Oak Ridge, TN)

1994-01-01

73

Thin Film Inorganic Electrochemical Systems.  

National Technical Information Service (NTIS)

During the 21 month period of this contract we have studied components for an all inorganic thin film lithium ion cell. During this work we have determined that thin film cathodes of LiCoO2 can be readily performed by either spray pyrolysis or spin coatin...

D. M. Schleich

1995-01-01

74

Thin film research. Volume 2  

Microsoft Academic Search

Optical thin films are important components in a range of technologies, ranging from energy conversion to information storage. In response to the demand for increasingly specialized and durable coatings, study of the basic nature of these coatings has intensified. This type of effort is necessary because assumptions that thin films were similar to nominally identical bulk materials have proven unreliable.

H. A. MacLeod

1985-01-01

75

Thin film ion conducting coating  

DOEpatents

Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.

Goldner, Ronald B. (Lexington, MA); Haas, Terry (Sudbury, MA); Wong, Kwok-Keung (Watertown, MA); Seward, George (Arlington, MA)

1989-01-01

76

Film-substrate interactions in Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7[minus]x] superconductor thin films deposited on oxide and alkaline earth fluoride substrates  

Microsoft Academic Search

Film-substrate interactions of Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7[minus]x] (YBCO) thin films grown by pulsed laser deposition on lanthanum aluminate (LaAlO[sub 3]), neodymium gallate (NdGaO[sub 3]), sapphire (Al[sub 2]O[sub 3]) and alkaline earth fluoride (BaF[sub 2], CaF[sub 2], MgF[sub 2], SrF[sub 2]) substrates were investigated. XPS, AFM, RBS, and XRD measurements showed that the quality of the film and amount of

1993-01-01

77

Evolution of structural perfections in high Tc superconducting thin film  

NASA Astrophysics Data System (ADS)

In this dissertation work, I developed a forensic methodology to investigate the evolution of chemistry and superconductivity in a heteroepitaxial thin film system---YBa2Cu3O6+x (YBCO). Misfit lattice of a YBCO thin film and its substrate results in coherency strain that dictates the generation of oxygen deficiency and structural defects, which is eventually manifested in the superconductivity or normal state properties. To understand the dynamic process of such evolution, in my retrospective approach, a thicker film is stripped thinner step by step and then compared with an as-grown film of equal thickness. Through such one-to-one comparison, I succeeded in characterizing the effects of strain, partial strain-relaxation, and complete strain-relaxation on the chemistry and physics of thin film cuprate high temperature superconductors as probed by various analytical tools.

Seo, Hye-Won

78

Thin film hydrogen sensor  

DOEpatents

A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.

Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.

1994-11-22

79

Film-substrate interactions in Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7[minus]x] superconductor thin films deposited on oxide and alkaline earth fluoride substrates  

SciTech Connect

Film-substrate interactions of Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7[minus]x] (YBCO) thin films grown by pulsed laser deposition on lanthanum aluminate (LaAlO[sub 3]), neodymium gallate (NdGaO[sub 3]), sapphire (Al[sub 2]O[sub 3]) and alkaline earth fluoride (BaF[sub 2], CaF[sub 2], MgF[sub 2], SrF[sub 2]) substrates were investigated. XPS, AFM, RBS, and XRD measurements showed that the quality of the film and amount of chemical reaction between film and substrate were dependent on the substrate material an deposition temperature. The reaction of Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7[minus]x] films with CaF[sub 2] and MgF[sub 2] substrates forms BaF[sub 2] and calcium or magnesium oxide species. The reacted film is insulating and has a microscopically rough surface. Deposition of YBCO films on Al[sub 2]O[sub 3] at high substrate temperature promotes film substrate interdiffusion resulting in an insulating material similar to the fluoride reaction products. No reaction was detected in films deposited on BaF[sub 2], SrF[sub 2], LaAlO[sub 3] or NdGaO[sub 3] and most of these films were superconducting with transition temperatures as high as 90 K. Deposition of an oxide buffer layer prevents film-substrate reactions on reactive substrates. XRD measurements show that the crystalline orientation of YBCO films deposited on LaAlO[sub 3] depends on deposition temperature. AFM images of very thin films show that YBCO grows on LaAlO[sub 3] and Al[sub 2]O[sub 3] by a 3D growth mechanism. In films deposited on LaAlO[sub 3] AFM shows that surface roughness and the diameter of surface domains increase at high deposition temperature.

Peters, C.H.

1993-01-01

80

Multilayered Thin Film Insulator for Harsh Environments.  

National Technical Information Service (NTIS)

The status of work to develop a reliable high temperature dielectric thin film for use with thin film sensors is presented. The use of thin films to electrically insulate thin film sensors on engine components minimizes the intrusiveness of the sensor and...

J. D. Wrbanek G. C. Fralick C. A. Blaha A. R. Busfield V. D. Thomas

2002-01-01

81

Thin Film Microcircuits for Rocketsonde.  

National Technical Information Service (NTIS)

Final resistor load life data are presented showing the differences between the epoxy and acrylic protected and unprotected tantalum thin film resistors. Preliminary studies are reported on the effects of the protective systems on the capacitance, dissipa...

B. J. Patton A. Smith

1966-01-01

82

Interference Colors in Thin Films.  

ERIC Educational Resources Information Center

|Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)|

Armstrong, H. L.

1979-01-01

83

Interference Colors in Thin Films.  

ERIC Educational Resources Information Center

Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)

Armstrong, H. L.

1979-01-01

84

Thin-film solar cells  

Microsoft Academic Search

The rapid progress that is being made with inorganic thin-film photovoltaic (PV) technologies, both in the laboratory and in industry, is reviewed. While amorphous silicon based PV modules have been around for more than 20 years, recent industrial developments include the first polycrystalline silicon thin-film solar cells on glass and the first tandem solar cells based on stacks of amorphous and

Armin G. Aberle

2009-01-01

85

Mechanical properties of thin films  

Microsoft Academic Search

The mechanical properties of thin films on substrates are described and studied. It is shown that very large stresses may\\u000a be present in the thin films that comprise integrated circuits and magnetic disks and that these stresses can cause deformation\\u000a and fracture to occur. It is argued that the approaches that have proven useful in the study of bulk structural

William D. Nix

1989-01-01

86

Novel thin film thermophotovoltaic system  

Microsoft Academic Search

We describe a novel design of a thermophotovoltaic (TPV) system based on thin film photocells. The radiation source is a selective emitter made from Yb2O3, which allows the use of photocells with a band gap between 1.0 and 1.2eV. Thin film solar cell materials like microcrystalline Si or Cu(In,Ga)Se2 (CIGS) can in principle be used for such a system. So

Wilhelm Durisch; Bernd Bitnar

2010-01-01

87

Thin films in energy systems  

Microsoft Academic Search

The development and use of thin plastic films as structural materials is discussed. The employment of air supported structure greenhouses utilizing very low cost highly transparent plastic film with a good life potential makes it possible to raise tomatoes in Ohio at costs which are much lower than those incurred in connection with the use of glass greenhouses. Attention is

R. S. Ross

1976-01-01

88

Effect of microstructure on thermal conductivity of Cu, Ag thin films.  

PubMed

Thin film type materials are widely used in modern industries, such as semiconductor devices, functional superconductors, machining tools, and so on. The thermal properties of material in semiconductor are very important factors for stable operation because the heat generated during device operation may increase clock frequency. Even though thermal properties of thin films may play a major role in assessing reliability of parts, the measurement methods of thin film thermal properties are generally known to be complex to devise. In this study, a temperature distribution method was applied for the measurement of thermal conductivity of Cu and Ag thin film on borosilicate glass substrate. Cu and Ag thin films were deposited on borosilicate glass using thermal evaporation processes. To measure the thermal conductivity changes according to the microstructure of metallic thin film, the processing variables for the Cu and Ag thin film deposition were changed. To minimize the effect of film thickness, the film thickness was fixed to the thickness of approximately 500 nm throughout experiments. The thermal conductivities of thin films were measured to be much lower than those of bulk materials. Thin film with larger grain size showed higher thermal conductivity probably due to the lower number density of grain boundary. Weidman-Franz law could be applied to thin films produced in this study. Thermal conductivity was also estimated from the resistivity of thin film and Lorenz number of bulk material. PMID:20358967

Ryu, Sang; Juhng, Woonam; Kim, Youngman

2010-05-01

89

Magnetism of nanostructured thin films  

NASA Astrophysics Data System (ADS)

Nanostructured magnetic materials have unique properties that are different from bulk materials. They are of great scientific interest, as provide many potential applications. This thesis presents the structural and magnetic properties of FePt thin films and FePt-based nanocomposite thin films. FePt thin films were deposited by magnetron sputtering. By annealing the as-deposited films, high-anisotropy L10 FePt films were obtained. The fcc to fct phase transition is dependent on the annealing temperature and time, as well as the composition of the films. In slightly Fe-rich films, a certain degree of (001) texture has been observed. The magnetic properties are dependent on the degree of structure ordering of the films. The relationship between the coercivity and the long-range-order parameter has been investigated. Because of the high anisotropy energy of the L10 phase, FePt films with large coercivity have been obtained. High anisotropy films are potential candidates for extremely high-density magnetic recording media. High- density recording requires media with small grain size. In FePt films, the annealing processes may result in the unfavorable grain growth. Nanocomposite films FePt:SiO2 and FePt:B2O 3 have been fabricated with fine FePt L10 particles embedded in the SiO2 or B2O3 matrix. The presence Of SiO2 or B2O3 suppresses the grain growth, resulting in films with grain size less than 10 run. The structure and magnetic properties of these films are dependent on the processing temperatures and the FePt volume fractions, as well as the matrix materials. For the FePt:SiO 2 nanocomposite films, the required processing temperature is high and the FePt particles are mostly randomly oriented. However, in FePt:B2 O3 nanocomposite films, the processing temperature can be reduced to 500°C because of the low melting point of B2O 3, Furthermore, the easy axes of the FePt particles can be made either in the film-plane or in the film- normal direction, resulting in films with in-plane anisotropy or perpendicular anisotropy. The desired anisotropy direction, large anisotropy constant and coercivity, as well as fine grain size make these nanocomposite films promising candidates for high-density magnetic recording media.

Luo, Chunping

90

Thin film-based optical fiber sensors  

Microsoft Academic Search

Optical thin films can be deposited on side- and end-face of optical fiber, if these films are sensitive to ambient environments, optical refractive index changes in thin films will finally result to variation of optical signals transmitted in the optical fiber. Here thin films work as sensitive elements and transducer to get response and feedback from environments, optical fiber here

Minghong Yang; Dai Jixiang; Wang Min; Xinling Tong; Desheng Jiang

2010-01-01

91

Thin-film metal hydrides.  

PubMed

The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis. PMID:18980236

Remhof, Arndt; Borgschulte, Andreas

2008-12-01

92

Electrodeposition and characterization of Y-Ba-Cu-O superconducting thin films  

Microsoft Academic Search

Precursor thin films of Y-Ba-Cu-O superconductor were produced by potentiostatic and pulse electrodeposition from the dissolved nitrate salts of Y, Ba, Cu in dimethylformamide (DMF). The films were deposited on metal foils such as Ag-coated Cu, Ag, Ni, and Zr. Films were also synthesized on Ag-coated SrTiOâ, CaTiOâ, and AlâOâ. The electrodeposited films were heat treated in flowing Oâ in

Weston

1991-01-01

93

Thin films under chemical stress  

SciTech Connect

The goal of work on this project has been develop a set of experimental tools to allow investigators interested in transport, binding, and segregation phenomena in composite thin film structures to study these phenomena in situ. Work to-date has focuses on combining novel spatially-directed optical excitation phenomena, e.g. waveguide eigenmodes in thin dielectric slabs, surface plasmon excitations at metal-dielectric interfaces, with standard spectroscopies to understand dynamic processes in thin films and at interfaces. There have been two main scientific thrusts in the work and an additional technical project. In one thrust we have sought to develop experimental tools which will allow us to understand the chemical and physical changes which take place when thin polymer films are placed under chemical stress. In principle this stress may occur because the film is being swelled by a penetrant entrained in solvent, because interfacial reactions are occurring at one or more boundaries within the film structure, or because some component of the film is responding to an external stimulus (e.g. pH, temperature, electric field, or radiation). However all work to-date has focused on obtaining a clearer understanding penetrant transport phenomena. The other thrust has addressed the kinetics of adsorption of model n-alkanoic acids from organic solvents. Both of these thrusts are important within the context of our long-term goal of understanding the behavior of composite structures, composed of thin organic polymer films interspersed with Langmuir-Blodgett (LB) and self-assembled monolayers. In addition there has been a good deal of work to develop the local technical capability to fabricate grating couplers for optical waveguide excitation. This work, which is subsidiary to the main scientific goals of the project, has been successfully completed and will be detailed as well. 41 refs., 10 figs.

Not Available

1991-01-01

94

Characterization of sculptured thin films  

SciTech Connect

Physical vapor deposition can be used to synthesize sculptured thin films with high surface areas. Highly directional vapor deposition onto a tilted, rotating substrate has been shown to produce nanostructured materials with controlled columnar features, including zig-zag, cusp, chevron, and helical geometries. Nanoporous coatings such as these are desirable for optical sensing applications due to their accessible high surface area, but few techniques are available to quantify the surface area of thin films. Electron beam and thermal evaporation techniques are used to synthesize highly porous thin films from silicon dioxide and a germanium antimony selenide chalcogenide glass in order to explore their potential for optical applications in both the visible and infrared spectral ranges. Characterization has been performed using nitrogen adsorption isotherms obtained with a quartz crystal microbalance. It is shown that surface area can be increased up to 375 times that of a flat film by deposition at oblique angles. A nitrogen adsorption technique is introduced as a means to examine the porosity of sculptured thin films at a nanoscale.

Ryan, Joseph V.; Horn, Mark; Lakhtakia, Ashlesh; Pantano, C. G.

2004-05-11

95

Cr metal thin film memory  

NASA Astrophysics Data System (ADS)

As state of the art flash memory technologies scale down to sub 30 nm node, conventional floating gate flash memory approaches its physical scaling limit mainly because of the high gate coupling ratio (GCR) requirement to secure proper memory window. Here, we report a novel flash memory device called Cr metal thin film memory (MTFM) that can circumvent the GCR issue and extend flash memory scalability by employing Cr thin film as a storage layer. Cr metal thin film memory devices with simple and low temperature processes produced a wide memory window of 10 V at the +/-18 V voltage sweep with GCR of only 0.3. Such a large window can be adopted for multi-level cell operations, which can further increase the memory density. Also, retention measurement shows more than 10 years retention time due to higher energy barrier between Cr metal and tunnel oxide than conventional poly silicon and tunnel oxide. Cross section transmission electron microscope (TEM) images showed the structure and accurate dimensions of the Cr MTFM device with continuous Cr film and sharp interfaces. As for material characterizations, an amorphous like Cr phase was observed through TEM and x-ray diffraction (XRD). X-ray photoelectron spectroscopy (XPS) confirmed the Cr-Cr bond and Cr-O bond near the Cr surface after evaporation and rapid thermal annealing. This metal thin film memory may open a new route to achieve the terabit level flash memory.

Hong, Augustin J.; Kim, Jiyoung; Kim, Kyoungwhan; Wang, Yong; Xiu, Faxian; Jeon, Jaeseok; Park, Jemin; Rauda, Iris; Chen, Li-Min; Yang, Yang; Tolbert, Sarah; Zou, Jin; Wang, Kang L.

2011-09-01

96

Type II Film Superconductors for Power Applications.  

National Technical Information Service (NTIS)

A basic theoretical background of type II superconductors and an introduction into materials are presented. The requirements for these materials for Army power applications are analyzed and compared with the present availability of these materials. A seri...

H. J. Spitzer

1974-01-01

97

Engineering Fundamentals of Thin-Film Microelectronics.  

National Technical Information Service (NTIS)

The book contains an investigation of applied technological problems in the manufacture and design of thin-film microcircuits constituting a further improved development of printed circuit engineering. The conditions of obtaining the thin-film resistive, ...

N. K. Ivanov-Esipovich

1968-01-01

98

Semiconducting Polymers for Thin?Film Electronics  

Microsoft Academic Search

An overview of practical issues related to the adoption of semiconducting polymers in thin?film electronic devices is presented. Performance requirements for organic light emitting diodes, thin?film transistors and photovoltaic devices are reviewed.

Michael L. Chabinyc

2006-01-01

99

Memristive Properties of Thin Film Cuprous Oxide.  

National Technical Information Service (NTIS)

Memristive properties of thin film copper oxides with different grain sizes were characterized using tunneling atomic force microscopy (TUNA) and optical reflection measurements. The thin films containing copper ions of different chemical states were prep...

B. C. Castle

2011-01-01

100

Semiconductor-nanocrystal/conjugated polymer thin films  

DOEpatents

The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

Alivisatos, A. Paul (Oakland, CA); Dittmer, Janke J. (Munich, DE); Huynh, Wendy U. (Munich, DE); Milliron, Delia (Berkeley, CA)

2010-08-17

101

US Polycrystalline Thin Film Solar Cells Program.  

National Technical Information Service (NTIS)

The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R and D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells...

H. S. Ullal K. Zweibel R. L. Mitchell

1989-01-01

102

Thin film-coated polymer webs  

DOEpatents

The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.

Wenz, Robert P. (Cottage Grove, MN); Weber, Michael F. (Shoreview, MN); Arudi, Ravindra L. (Woodbury, MN)

1992-02-04

103

5. SUPERCONDUCTOR-METAL-INSULATOR TRANSITIONS: Vortex states at low temperature in disordered thin and thick films of a-MoxSi1-x  

Microsoft Academic Search

We have measured the ac complex resistivity in the linear regime, as well as dc resistivity, for thick (100, 300 nm) amorphous (a-)MoxSi1-x films at low temperatures (T > 0.04 K) in constant fields B. The critical behavior associated with the second-order transition has been observed for both dc and ac resistivities, which is similar to that observed for granular

S. Okuma; M. Morita

2001-01-01

104

Chemical preparation of powders and films for high temperature superconductors  

NASA Astrophysics Data System (ADS)

A precipitation process has been developed to prepare precursor powders which can be calcined and sintered to form high critical temperature superconductors such as YBa(sub 2)Cu(sub 3)O(sub 7-x). Precursor powders are prepared using a continuous precipitation system in which a solution containing highly soluble salts of the desired metal cations is rapidly and completely mixed with a solution containing precipitating anions such as hydroxide and carbonate ions. The resulting amorphous powder can be calcined to form submicron particles of desired superconducting phases which are useful in preparing inks for the ink-jet printing of superconducting interconnects. The powders can be redissolved in organic solvents to form solutions which can be used in spin or dip coating substrates with thin superconducting films. Finally, the powders have been used to prepare bulk ceramics which exhibit the highest reported critical currents of any chem-prep ceramics. Bulk samples prepared from chloride doped precursors exhibit large, oriented grains and extensive flux pinning.

Bunker, B. C.; Voigt, J. A.; Lamppa, D. L.; Doughty, D. H.; Venturini, E. L.; Kwak, J. F.; Ginley, D. S.; Headley, T. J.; Harrington, M. S.; Eatough, M. O.

105

Thin Film Cell Development Workshop Report.  

National Technical Information Service (NTIS)

The Thin Film Development Workshop provided an opportunity for those interested in space applications of thin film cells to debate several topics. The unique characteristics of thin film cells as well as a number of other issues were covered during the di...

J. R. Woodyard

1991-01-01

106

Electrical properties of ultra thin polypropylene film  

Microsoft Academic Search

Ultra thin polypropylene (PP) films (thickness: 10~100 nm) are deposited on a glass substrate by the vacuum evaporation method. The temperature of the glass substrate is kept at room temperature or 100°C during the deposition. The ESCA data revealed that a ultra thin PP film (thin PP film) is not only oxidized on the surface but also in the bulk.

T. Ogawa; S. Ochiai; T. Takagi; K. Kojima; M. Ieda; T. Mizutani

1994-01-01

107

Columnar growth in thin films  

SciTech Connect

A theory for the growth of columnar microstructures in thin films is presented. The zone-I to zone-II transition temperature is predicted. The surface morphology and the columnar grain structure are obtained both analytically and numerically, and the scaling behavior of the columnar grain size with film thickness is derived. Monte Carlo simulations are used to follow the evolution of the three-dimensional zone-II microsctuctures and to account for the formation of film texture. These results agree with experimental observations.

Mazor, A.; Srolovitz, D.J.; Hagan, P.S.; Bukiet, a.B.G.

1988-02-01

108

Preparation of epitaxial Y-Ba-Cu-O thin films by pulsed ion-beam evaporation  

Microsoft Academic Search

Summary form only given, as follows. YBa2Cu3O7-? (Y-123) high-Tc superconductor has excellent critical current density characteristics and thin films of Y-123 has been prepared by various methods. However, the deposition rate was limited and the increase in the deposition rate has been desired. A novel thin film deposition method has been developed, which is named as ion-beam evaporation (IBE). Extremely

H. Suematsu; G. Yoshida; S. Sorasit; T. Suzuki; W. Jiang; K. Yatsui

2001-01-01

109

Proximity effect in MBE grown bismuth chalcogenide thin films  

NASA Astrophysics Data System (ADS)

Topological insulators (TIs) comprise a new state of matter which provides access to novel physics. Of the set of materials that have exhibited spectroscopic evidence of topologically protected surface states, bismuth chalcogenide systems have garnered particular interest due to their relatively large nominal bulk band gap and single Dirac cone near the Fermi surface. We are studying the superconducting proximity effect in MBE grown thin films of Bi2Se3, Bi2Te3, and ternary compounds. After in situ deposition of a low temperature superconductor, the films are patterned into devices containing a matrix of superconducting islands of tunable size and density on top of the TI layer. We discuss growth optimization, device processing, the role of the superconductor-TI interface, and proximity effect transport results.

Mulcahy, Brian; Zheng, Mao; Zhang, Can; Dove, Allison; Yoscovits, Zachary R.; Olson, Gustaf; Eckstein, James N.

2013-03-01

110

Characterization of sculptured thin films  

Microsoft Academic Search

Physical vapor deposition can be used to synthesize sculptured thin films with high surface areas. Highly directional vapor deposition onto a tilted, rotating substrate has been shown to produce nanostructured materials with controlled columnar features, including zig-zag, cusp, chevron, and helical geometries. Nanoporous coatings such as these are desirable for optical sensing applications due to their accessible high surface area,

Joseph V. Ryan; Mark W. Horn; Akhlesh Lakhtakia; Carlo G. Pantano

2004-01-01

111

Thin film polymeric gel electrolytes  

DOEpatents

Novel hybrid thin film electrolyte, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities .apprxeq.10.sup.-3 .OMEGA..sup.-1 cm.sup.-1 are useful as electrolytes for rechargeable lithium batteries.

Derzon, Dora K. (1554 Rosalba St. NE., Albuquerque, Bernalillo County, NM 87112); Arnold, Jr., Charles (3436 Tahoe, NE., Albuquerque, Bernalillo County, NM 87111); Delnick, Frank M. (9700 Fleming Rd., Dexter, MI 48130)

1996-01-01

112

Thin film polymeric gel electrolytes  

DOEpatents

Novel hybrid thin film electrolytes, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities {approx_equal}10{sup {minus}3}{Omega}{sup {minus}1} cm{sup {minus}1} are useful as electrolytes for rechargeable lithium batteries. 1 fig.

Derzon, D.K.; Arnold, C. Jr.; Delnick, F.M.

1996-12-31

113

Lessons from Oxypnictide Thin Films  

NASA Astrophysics Data System (ADS)

First experiments on the growth of oxypnictide F-doped LaFeAsO thin films indicated an incomplete normal-to-superconducting transition and offered a work programme challenging to overcome possible difficulties in their fabrication. In this regard the possibility of an all in-situ epitaxial growth appeared to be a matter of time and growth parameters. The following review clarifies that F-doped oxypnictide thin films are extremely difficult to grow by in-situ PLD due to the formation of very stable impurity phases such as oxyfluorides (LaOF) and oxides (La2O3) and the loss of stoichiometry possibly due to incongruent evaporation of the target or re-evaporation of volatile elements at the substrate surface. However, the review also demonstrates that the employed two-step fabrication process for oxypnictide thin films has been successfully applied in the preparation of clean polycrystalline as well as of epitaxial thin films. Fundamental investigations on the upper critical field, its temperature dependence and its anisotropy contributed to an understanding of multiband superconductivity in oxypnictides.

Haindl, Silvia; Kidszun, Martin; Onken, Franziska; Mietke, Alexander; Thersleff, Thomas

2013-02-01

114

Disentanglement in thin polymer films  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulations of thin polymer films confined between structureless walls show accelerated in-plane dynamics with decreasing film thickness. Using the primitive path analysis (PPA) introduced by Everaers et al [Science 303 (2004) 823] for chain length up to N=1024, we can show that the entanglement density decreases with decreasing film thickness. However, the effect becomes pronounced only for films thinner than the bulk radius of gyration where also the chain structure becomes modified by the confinement [1]. The PPA algorithm can be modified to estimate the contribution of self-entanglements: The latter become more important for thinner films, however, they do not counterbalance the global decrease of entanglements. [1] H. Meyer et al Eur. Phys. J. Sp.Top. 141 (2007) 167.

Meyer, Hendrik

2008-03-01

115

Cellulose Triacetate, Thin Film Dielectric Capacitor.  

National Technical Information Service (NTIS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electr...

S. S. Yen T. R. Jow

1993-01-01

116

Method of producing thin films of silicon  

SciTech Connect

A method of producing thin films of silicon is characterized in that a p-type or n-type thin film of doped silicon having a dopant or impurity element is placed in a plasma atmosphere of elements selected from the group consisting of fluorine, chlorine, bromine, iodine, and hydrogen, whereby the concentration of an impurity element in the thin film is decreased adjacent to the surface of thin film and accordingly the impurity element is replaced by the plasma element adjacent to the surface of the thin film.

Tanaka, K.; Matsuda, A.; Yoshida, T.

1985-12-25

117

Sputtered Thin Film Research.  

National Technical Information Service (NTIS)

Progress on the process development as it relates to the optical quality of sputtered single crystal films of ZnO, AlN, and TiO2 is discussed. Optical attenuation data for optical waveguide structures comprised of zinc oxide, aluminum nitride, titanium di...

A. J. Shuskus D. J. Quinn E. L. Paradis J. M. Berak D. E. Cullen

1973-01-01

118

Application of YIG film to thin film inductors  

Microsoft Academic Search

The application of YIG (yttrium iron garnet) films to thin film inductors is examined up to 1 GHz. The application of a YIG film to thin film inductors made it possible to increase the inductance without increasing the stray capacitance. The sandwich-type YIG inductor exhibited an inductance 40 times larger than that of a similar air core inductor. The inductance

K. I. Arai; M. Yamaguchi; H. Ohzeki; M. Matsumoto

1991-01-01

119

Thin film lithium batteries  

Microsoft Academic Search

New electrolyte materials, polymers or inorganic glasses, allow the design of flat lithium primary or secondary batteries for miniaturised devices from smart cards to CMOS back up. The so-called “hybrid plastic electrolytes” allow the design of thick film cells (1–3 mm) with a surface capacity of some mA h cm?2. For Li-ion secondary batteries, the number of cycles does not

Jean Louis Souquet; Michel Duclot

2002-01-01

120

Analytical Solution for Thin-Film Flows  

Microsoft Academic Search

Thin-films provide a potential explanation for a very fast transport of fluids through unsaturated fractured porous media. Such films may appear in air-filled fractures, although they appear in other instances too. Fluid and contaminants can be transported significant distances over short time intervals with thin-film flows. We present an analytical solution for the distribution of a solute in thin-film flows.

A. S. Telyakovskiy; K. M. Hayden; S. W. Wheatcraft

2008-01-01

121

Electrical properties of ultra thin polymer films  

Microsoft Academic Search

Ultra thin polyamide (PA) films (thickness: 2~3 nm) were deposited on a glass substrate by the vacuum evaporation method. The evaporated PA thin film was annealed at 200°C for one hour in nitrogen. The FT-IR spectrum of the ultra thin film agreed well with that of a conventional PA film, which suggests that the structure of the two types of

A. Maeda; L. Zhu; T. Kato; H. Furuhashi; T. Yoshikawa; A. Ohashi; K. Kojima; Y. Uchida; S. Ochiai; M. Ieda; T. Mizutani

1997-01-01

122

Thin film buried anode battery  

DOEpatents

A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

Lee, Se-Hee (Lakewood, CO); Tracy, C. Edwin (Golden, CO); Liu, Ping (Denver, CO)

2009-12-15

123

YBaCuO thin films on Si substrate  

NASA Astrophysics Data System (ADS)

YBa2Cu3O7-x(YBaCuO) films of 200nm thickness of Si substrates covered by 20nm ZrO2 were prepared by two-laser ablation technique. The influence of the ZrO2 buffer sublayer preparation conditions on Si diffusion into high-temperature super-conductor (HTSC) film were investigated. To overcome the diffusion process we proposed and realized two approaches. First: a homoepitaxy technique of HTSC film deposition. Second:a two-step ZrO2 sublayer creation technique. The critical temperature Tc(R=0) of the YBaCuO thin films on Si substates was as high as 88, 5 K.

Krasnosvobodtsev, S. I.; Pechen, E. V.

1991-12-01

124

Bismuth ferrite composite thin films  

NASA Astrophysics Data System (ADS)

0.60Bi0.90La0.10FeO3-0.40Pb(Zr0.52Ti0.48)O3 composite thin films were deposited on Pt/TiO2/SiO2/Si(100) substrates by radio-frequency sputtering and their ferroelectric and fatigue properties were mainly investigated. The composite thin films have a low dielectric loss, a high dielectric constant, and enhanced ferroelectric properties of 2 P r˜122.6 ?C/cm2 and 2 E c˜479.3 kV/cm, together with a fatigue-free behavior at 200 kHz. Their fatigue behavior is strongly dependent on measurement frequencies, and the concentration of oxygen vacancies plays an important role in their fatigue behavior.

Wu, Jiagang; Zhang, Binyu; Wang, Xiaopeng

2013-06-01

125

Prospects for electronic applications of rare-earth-free superconducting thin films  

Microsoft Academic Search

Thin films of the high-Tc superconductors Bi-Ca-Sr-Cu-O and Tl-Ca-Ba-Cu-O were prepared and characterized. A zero resistance state was achieved at 116 K in the Tl-Ca-Ba-Cu-O films. The crystal structures of these films are pseudo-tetragonal, so that the surface morphologies are essentially twin free. Using a SQUID magnetization measurement in a parallel field, a randomly oriented polycrystalline Tl-Ca-Ba-Cu-O thin film showed

Masao Nakao

1989-01-01

126

Pulsed laser deposition of high Tc superconducting thin films: Present and future  

SciTech Connect

Pulsed laser deposition (PLD) has been widely used for deposition of high {Tc} superconducting thin films, and has been approved as one of the best physical vapor techniques to prepare the films. The most important advantage of this technique is stoichiometric deposition, namely the films could be made with the same composition of the targets. Utilized PLD, not only thin films but also multilayers and superlattices of high {Tc} superconductors have been fabricated. In this paper, the performance of the technique will be reviewed, and the future will be speculated.

Wu, X.D.; Muenchausen, R.E.; Foltyn, S.; Estler, R.C.; Dye, R.C.; Garcia, A.R.; Nogar, N.S. (Los Alamos National Lab., NM (USA)); Venkatesan, T.; Chang, C.C.; Ramesh, R.; Hwang, M.; Nazar, L.; Wilkens, B.; Schwarz, S.A.; Ravi, R.T.; Barner, J.B.; England, P.; Rogers, C.T.; Tarascon, J.M. (Bellcore, Red Bank, NJ (USA)); Inam, A.; Xi, X.X.; Li, Q. (Rutgers--the State Univ., Piscataway, NJ (USA). Dept. of Physics and

1990-01-01

127

Electrochemically deposited bismuth telluride thin films  

Microsoft Academic Search

Thin films of bismuth telluride grown by electrochemical deposition technique on conducting glass and Mo sheet substrates, were characterized for their structural, morphological, optical and compositional analysis. These studies revealed polycrystalline anisotropic and layered structure of these films with different compositional stoichiometry. In the present work electrochemical deposition of bismuth telluride thin films is studied as a dopant material in

Santosh Golia; M. Arora; R. K. Sharma; A. C. Rastogi

2003-01-01

128

High-Tc Superconducting Thin Film Devices.  

National Technical Information Service (NTIS)

In this dissertation, a number of approaches were explored for the fabrication of high-Tc superconducting ultra-thin films and multilayer thin films by using pulsed laser deposition and reactive molecular beam epitaxy with an ozone source. With these film...

Z. W. Dong

1995-01-01

129

Magnetocaloric Effect in Thin Films and Heterostructures  

Microsoft Academic Search

The goals of this work are the optimization of the magnetocaloric effect in Gadolinium thin film structures. We approach this issue from two directions, that of process optimization and of interface effects. Past results showed Gd2O3 in our Gadolinium thin films, and the presence of such oxide seemed to grow with the temperature at which the film was grown or

Christopher Bauer

2011-01-01

130

Microwave response of vortices in superconducting thin films of Re and Al  

Microsoft Academic Search

Vortices in superconductors driven at microwave frequencies exhibit a response related to the interplay between the vortex viscosity, pinning strength, and flux creep effects. At the same time, the trapping of vortices in superconducting microwave resonant circuits contributes excess loss and can result in substantial reductions in the quality factor. Thus, understanding the microwave vortex response in superconducting thin films

C. Song; T. W. Heitmann; M. P. Defeo; K. Yu; R. McDermott; M. Neeley; John M. Martinis; B. L. T. Plourde

2009-01-01

131

TTF[Ni(dmit)2]2: Now as Thin Films and Nanowires  

NASA Astrophysics Data System (ADS)

Thin films and nanowires of the molecular superconductor TTF[Ni(dmit)2]2 (TTF = tetrathiafulvalene, dmit2-=2-thioxo-1,3-dithiol-4,5-dithiolato) are obtained by dipping process on stainless-steel and silicon conversion coatings and on a microrough silicon surface. The deposits are characterized by SEM, Raman spectroscopy and conductivity measurements.

Valade, Lydie; Casellas, Hélène; Roques, Stéphane; Faulmann, Christophe; de Caro, Dominique; Zwick, Antoine; Ariès, Lucien

2002-11-01

132

Thermal isolation of high-temperature superconducting thin films using silicon wafer bonding and micromachining  

Microsoft Academic Search

Using a new micromachining technology, thermally isolated thin films of high-temperature superconductor have been microfabricated. The intended application for these structures is in infrared bolometers. A silicon wafer bonding process produces a low thermal mass island of single-crystal silicon on a silicon nitride membrane which provides thermal isolation. The silicon can act as a seed for the epitaxial growth of

Christopher A. Bang; Joseph P. Rice; Markus I. Flik; David A. Rudman; Martin A. Schmidt

1993-01-01

133

Preparation of thin ceramic films via an aqueous solution route  

DOEpatents

A new chemical method of forming thin ceramic films has been developed. An aqueous solution of metal nitrates or other soluble metal salts and a low molecular weight amino acid is coated onto a substrate and pyrolyzed. The amino acid serves to prevent precipitation of individual solution components, forming a very viscous, glass-like material as excess water is evaporated. Using metal nitrates and glycine, the method has been demonstrated for zirconia with various levels of yttria stabilization, for lanthanum-strontium chromites, and for yttrium-barium-copper oxide superconductors on various substrates.

Pederson, Larry R. (Kennewick, WA); Chick, Lawrence A. (Richland, WA); Exarhos, Gregory J. (Richland, WA)

1989-01-01

134

Method of producing amorphous thin films  

DOEpatents

Disclosed is a method of producing thin films by sintering which comprises: (a) coating a substrate with a thin film of an inorganic glass forming material possessing the capability of being sintered; and (b) irradiating said thin film of said particulate material with a laser beam of sufficient power to cause sintering of said material below the temperature of liquidus thereof. Also disclosed is the article produced by the method claimed. 4 figs.

Brusasco, R.M.

1992-09-01

135

Flux-flow-type Josephson oscillator for millimeter and submillimeter wave region. IV - Thin-film coupling  

NASA Astrophysics Data System (ADS)

Power emission from a flux-flow-type Josephson oscillator with a thin-film coupling method is studied experimentally. The thickness of one electrode of the oscillator is made thin enough to allow electromagnetic fields generated by the oscillator to be emitted through the thin-film electrode. Radiation power from the oscillator is detected with superconductor-insulator-superconductor detectors, which are fabricated on top of the oscillator. Experimental results show that sufficient power can be obtained from the oscillator by using the thin-film coupling method when the thickness of the electrode is comparable to the London penetration depth. The results obtained are in reasonable agreement with theoretical predictions. The thin-film coupling method will be useful when the oscillator is connected to external circuits, such as an impedance matching circuit.

Qin, J.; Enpuku, K.; Yoshida, K.

1988-02-01

136

Growth Optimization of Zinc Phthalocyanine Thin Films fo High Performance Thin Film Transistor  

Microsoft Academic Search

The morphology of thermally evaporated zinc phthalocynine (ZnPc) organic thin films were engineered for obtaining high performance organic thin film transistor(OTFT) by varying substrate temperature and fixed deposition rate 0.1 A˚\\/sec. ZnPc thin films were characterized by X-ray diffraction (XRD) and atomic force microscopy. The output characteristic of organic thin film transistor shows the highest mobility in the device with

Sarita Yadav; Subhasis Ghosh

2011-01-01

137

Growth and oxygen doping of thin film FeTe by Molecular Beam Epitaxy  

NASA Astrophysics Data System (ADS)

FeTe is isomorphic to FeSe, a representative of the 11 family of iron based superconductors. While not a superconductor itself, FeTe, particularly in thin film form, undergoes a superconducting transition when doped with oxygen. In this presentation, we will discuss the growth of FeTe by MBE and various schemes we used to dope the samples. Evidence from our investigation suggests that FeTe films are doped via an oxygen diffusion process which is strongly activated by temperature.

Zheng, Mao; Zhang, Can; Hu, Hefei; Zuo, Jian-Min; Eckstein, James

2012-02-01

138

Microwave properties of YBCO thin films  

Microsoft Academic Search

We have measured the microwave properties of high quality YBCO thin films using a copper cavity (87 GHz) and a dielectric resonator (19 GHz) for unpatterned films as well as a coplanar resonator (5, 8, 10, 15 and 16 GHz) for patterned films. For the patterned films the surface resistance (RS) and non-linear effects were studied as a function of

B. Avenhaus; A. Porch; M. J. Lancaster; S. Hensen; M. Lenkens; S. Orbach-Werbig; E. Muller; U. Dahne; N. Tellmann; N. Klein; C. Dubourdieu; J. P. Senateur; O. Thomas; H. Karl; B. Stritzker; J. A. Edwards; R. Humphreys

1995-01-01

139

Fabrication of micro-thin film thermocouples  

Microsoft Academic Search

We fabricated thin film thermocouples (TFTCs) to measure temperature distributions at the micro-scale. Nickel film was deposited as the first thermocouple material. Silicon dioxide was then deposited on the Ni film as an insulator. To make the thermocouple junctions, micro-holes were opened by focused ion beam (FIB), and tungsten film was patterned on the insulator as the. second thermocouple material.

K. Miyazaki; T. Takamiya; H. Tsukamoto

2003-01-01

140

Analytical Solution for Thin-Film Flows  

NASA Astrophysics Data System (ADS)

Thin-films provide a potential explanation for a very fast transport of fluids through unsaturated fractured porous media. Such films may appear in air-filled fractures, although they appear in other instances too. Fluid and contaminants can be transported significant distances over short time intervals with thin-film flows. We present an analytical solution for the distribution of a solute in thin-film flows. Various initial distributions of solute are considered. The new analytical solution provides explicit formulas for the average concentration of solute in the steady-state film.

Telyakovskiy, A. S.; Hayden, K. M.; Wheatcraft, S. W.

2008-12-01

141

Self-injection length in La 0.7 Ca 0.3 MnO 3 -YBa 2 Cu 3 O 7-? ferromagnet-superconductor multilayer thin films  

Microsoft Academic Search

We have carried out extensive studies on the self-injection problem in barrierless heterojunctions between La0.7Ca0.3MnO3 (LCMO) and YBa2Cu3O7-? (YBCO) thin films. The heterojunctions were formed in situ by sequentially growing LCMO and YBCO films on ?100? LaAlO3 (LAO) substrate using a pulsed laser deposition (PLD) system. YBCO micro-bridges with 64 µm width were patterned both on\\u000a the LAO (control) and

S. P. Pai; S. Wanchoo; S. C. Purandare; T. Banerjee; P. R. Apte; A. M. Narsale; R. Pinto

2002-01-01

142

Grain growth of rapid-thermal-annealed Y-Ba-Cu oxide superconducting thin films  

Microsoft Academic Search

A study of the microstructure of Cu-rich and stoichiometric Y-Ba-Cu oxide thin-film superconductors is presented. The films were deposited on ?100? SrTiO3 by the nonvacuum technique of metalorganic deposition followed by rapid thermal annealing in oxygen. Analysis showed that for annealing temperatures below 900 °C, grain size increased with increased annealing temperature, with an enhancement in grain growth for the

A. H. Hamdi; J. V. Mantese; A. L. Micheli; R. A. Waldo; Y. L. Chen; C. A. Wong

1988-01-01

143

Grain growth of rapid-thermal-annealed Y-Ba-Cu oxide superconducting thin films  

Microsoft Academic Search

A study of the microstructure of Cu-rich and stoichiometric Y-Ba-Cu oxide thin-film superconductors is presented. The films were deposited on 100-line SrTiO3 by the nonvacuum technique of metalorganic deposition followed by rapid thermal annealing in oxygen. Analysis showed that for annealing temperatures below 900 C, grain size increased with increased annealing temperature, with an enhancement in grain growth for the

A. H. Hamdi; J. V. Mantese; A. L. Micheli; R. A. Waldo; Y. L. Chen; C. A. Wong

1988-01-01

144

Superconductive properties of thin dirty superconductor-normal-metal bilayers  

NASA Astrophysics Data System (ADS)

The theory of superconductivity in thin superconductor-normal-metal (SN) sandwiches (bilayers) in the diffusive limit is developed within the standard Usadel equation method, with particular emphasis on the case of very thin superconductive layers, dS<

Fominov, Ya. V.; Feigel'man, M. V.

2001-03-01

145

Superconductors  

NSDL National Science Digital Library

Superconductors.org, a non-profit, non-affiliated Website, provides this clear introduction to the world of superconductors. Starting appropriately with Heike Kamerlingh Onnes, the first man to observe superconductivity in 1911, a history of superconductors section familiarizes students and laymen with the development of materials that have no resistance to the flow of electricity. Subsequent sections include uses for superconductors, various types of superconductors, links to current superconductor news, and patents.

Eck, Joe

2003-10-10

146

Polyimide-based scintillating thin films  

Microsoft Academic Search

The production procedure and the scintillation characteristics of thin polyimide films containing rhodamine B are reported. Fluorinated polyimide has been chosen as host matrix for its well known radiation hardness, in order to improve the lifetime of detector systems based on plastic thin film scintillators, 6FDA (4,4'-hertafluoroisopropylidene diphthalic anhydride) and DAB (diaminobenzophenone) have been used as polyimide precursor monomers. The

A. Quaranta; S. Carturan; G. Maggioni; P. M. Milazzo; U. Abbondanno; G. Della Mea; F. Gramegna; U. Pieri

2001-01-01

147

Magnetic Properties of Materials and Thin Films  

SciTech Connect

Magnetic and electromagnetic properties of materials and thin films are used extensively. Applications include actuators, storage devices, memory devices, EMI shielding devices, smart sensors, and motors. Magnetism basics must first be understood before the magnetic properties of thin films can be discussed.

Martin, Peter M.

2005-03-15

148

Macro Stress Mapping on Thin Film Buckling.  

National Technical Information Service (NTIS)

Thin films deposited by Physical Vapor Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of thin film buckling in the case of compressive stresses. Since the 80's, a lot of theoretical work has been don...

P. Goudeau P. Villain P. O. Renault N. Tamura R. S. Celestre H. Padmore

2002-01-01

149

Fabrication and characterization of PDMS thin film  

Microsoft Academic Search

Because PDMS is viscous, it's impossible to form thin films of PDMS using spin coating without dilute it with solvents. We examine the optimal solvents and spin parameters for spin-coating the PDMS elastomer on glass substrates. Chloroform, Benzene, and Toluene have been attempted to study the influences of solvent on forming thin films of high uniformity. The experiments conclude: the

Shuping Wang; Ajay Kallur; Abeselom Goshu

2011-01-01

150

Effect of Substrate Composition on the Piezoelectric Response of Reactively Sputtered AlN Thin Films;Thin Solid Films.  

National Technical Information Service (NTIS)

Effect of substrate composition on the piezoelectric response of reactively sputtered AIN thin films of reactive radio frequency (RF) sputtered AIN thin films. We observed piezoelectric deposition of adjacent thin film layers appeared to have the greatest...

P. G. Clem D. B. Dimos D. M. Gonzales J. A. Ruffner B. A. Tuttle

1999-01-01

151

Characteristics Of Vacuum Deposited Sucrose Thin Films  

NASA Astrophysics Data System (ADS)

Thin films of sucrose (C12H22O11) were deposited on thin cut glass substrates by thermal evaporation technique (p ~ 10-5 torr). The surface morphology was putted into evidence by FT-IR and SEM analysis. The experimental results confirm a uniform deposition of an adherent sucrose layer. The biological tests (e.g., cell morphology and cell viability evaluated by measuring mitochondrial dehydrogenise activity with MTT assay) confirm the properties of sucrose thin films as bioactive material. The human fetal osteoblast system grown on thin sucrose film was used for the determination of cell proliferation, cell viability and cell morphology studies.

Ungureanu, F.; Predoi, D.; Ghita, R. V.; Vatasescu-Balcan, R. A.; Costache, M.

152

A monolithic thin film electrochromic window  

SciTech Connect

Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. (Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center); Wei, G. (Mobil Solar Energy Corp., Billerica, MA (United States)); Yu, P.C. (PPG Industries, Inc., Monroeville, PA (United States))

1991-01-01

153

A monolithic thin film electrochromic window  

SciTech Connect

Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. [Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center; Wei, G. [Mobil Solar Energy Corp., Billerica, MA (United States); Yu, P.C. [PPG Industries, Inc., Monroeville, PA (United States)

1991-12-31

154

Cellulose triacetate, thin film dielectric capacitor  

NASA Astrophysics Data System (ADS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

Yen, Shiao-Ping S.; Jow, T. Richard

1993-05-01

155

Cellulose triacetate, thin film dielectric capacitor  

NASA Astrophysics Data System (ADS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

Yen, Shiao-Ping S.; Jow, T. Richard

1995-08-01

156

Carbon nanotube based transparent conductive thin films.  

PubMed

Carbon nanotube (CNT) based optically transparent and electrically conductive thin films are fabricated on plastic substrates in this study. Single-walled carbon nanotubes (SWNTs) are chemically treated with a mixture of concentrated sulfuric acid and nitric acid before being dispersed in aqueous surfactant-contained solutions. SWNT thin films are prepared from the stable SWNT solutions using wet coating techniques. The 100 nm thick SWNT thin film exhibits a surface resistivity of 6 kohms/square nanometer with an average transmittance of 88% on the visible light range, which is three times better than the films prepared from the high purity as-received SWNTs. PMID:17025106

Yu, X; Rajamani, R; Stelson, K A; Cui, T

2006-07-01

157

Raman spectroscopy of thin films  

NASA Astrophysics Data System (ADS)

Raman spectroscopy was used in conjunction with x-ray diffraction and x-ray photoelectron spectroscopy to elucidate structural and compositional information on a variety of samples. Raman was used on the unique La 2NiMnO6 mixed double perovskite which is a member of the LaMnO3 family of perovskites and has multiferroic properties. Raman was also used on nanodiamond films as well as some boron-doped carbon compounds. Finally, Raman was used to identify metal-dendrimer bonds that have previously been overlooked. Vibrational modes for La2NiMnO6 were ascribed by comparing spectra with that for LaMnO3 bulk and thin film spectra. The two most prominent modes were labeled as an asymmetric stretch (A g) centered around 535 cm-1 and a symmetric stretch (B g) centered around 678 cm. The heteroepitaxial quality of La2NiMnO 6 films on SrTiO3 (100) and LaAlO3 (100) substrates were examined using the Raman microscope by way of depth profile experiments and by varying the thickness of the films. It was found that thin films (10 nm) had much greater strain on the LaAlO3 substrate than on the SrTiO3 substrate by examining the shifts of the Ag and the Bg modes from their bulk positions. Changes in the unit cell owing to the presence of oxygen defects were also monitored using Raman spectroscopy. It was found that the Ag and Bg modes shifted between samples formed with different oxygen partial pressures. These shifts could be correlated to changes in the symmetry of the manganese centers due to oxygen defects. Raman spectroscopy was used to examine the structural and compositional characteristics of carbon materials. Nanocrystalline diamond coated cutting tools were examined using the Raman Microscope. Impact, abrasion, and depth profile experiments indicated that delamination was the primary cause of film failure in these systems. Boron doped material of interest as catalyst supports were also examined. Monitoring of the G-mode and intensities of the D- and G-modes indicated that boron was successfully introduced into both a bulk powder fabricated in a quartz furnace using a BCl3/C6H 6 precursor and for a thin film (30 nm) deposited in a vacuum chamber using d.c. magnetron cosputtering. In addition to Raman, x-ray diffraction and x-ray photoelectron spectroscopy were used to verify boron-doping of the materials. Generation 4 Poly(amidoamine) dendrimers were used to form platinum and cobalt nanoparticles to form dendrimer-encapsulated nanoparticles (DENs). It was seen using both Raman and infrared spectroscopy that these metals bonded with the dendrimers after reduction. These studies highlight the efficacy of Raman in the study of a wide variety of materials to obtain both compositional and structural information.

Burgess, James Shaw

158

Characteristics of tin nitride thin-film negative electrode for thin-film microbattery  

Microsoft Academic Search

Tin nitride is a relatively unknown compound. In this study, the tin nitride thin film is examined as a negative electrode for a thin-film microbattery. Reactive rf magnetron sputtering is used for deposition of films with varying deposition temperature. The charge–discharge properties of thin films deposited at room temperature, 100 and 200°C are found to be satisfactory. As the irreversible

K. S. Park; Y. J. Park; M. K. Kim; J. T. Son; H. G. Kim; S. J. Kim

2001-01-01

159

Thin-film thermoelectric generator element characterization  

Microsoft Academic Search

A thermoelectric power generator using thin-film materials presents many challenges due to its inherently large temperature gradient and correspondingly large power density. We present measurements of generated power density from BiTe-based thin-film and thick-film single-element devices (Marlow) in a variety of different element lengths (150-1500 micron) with an experimental setup capable of generating a large temperature difference (>300 K) across

Peter Mayer; Rajeev J. Ram

2005-01-01

160

Electro-deposition of superconductor oxide films  

DOEpatents

Methods for preparing high quality superconducting oxide precursors which are well suited for further oxidation and annealing to form superconducting oxide films. The method comprises forming a multilayered superconducting precursor on a substrate by providing an electrodeposition bath comprising an electrolyte medium and a substrate electrode, and providing to the bath a plurality of precursor metal salts which are capable of exhibiting superconducting properties upon subsequent treatment. The superconducting precursor is then formed by electrodepositing a first electrodeposited (ED) layer onto the substrate electrode, followed by depositing a layer of silver onto the first electrodeposited (ED) layer, and then electrodepositing a second electrodeposited (ED) layer onto the Ag layer. The multilayered superconducting precursor is suitable for oxidation at a sufficient annealing temperature in air or an oxygen-containing atmosphere to form a crystalline superconducting oxide film.

Bhattacharya, Raghu N. (Littleton, CO)

2001-01-01

161

Polyamideimide polymer thin films for integrated optics  

Microsoft Academic Search

The applicability of a polyamide-imide (PAI) polymer to thin film optical applications was investigated. The polymer preparation and spin characteristics are described in detail. The films exhibited good adhesion to silicon, glass, and benzocyclobutene polymer. The refractive index was measured in the near infrared region. To demonstrate feasibility for devices, features were plasma etched into PAI films. Oversized inverted rib

R. M. Bryce; H. T. Nguyen; P. Nakeeran; T. Clement; C. J. Haugen; R. R. Tykwinski; R. G. DeCorby; J. N. McMullin

2004-01-01

162

Nitrogen Doped Zinc Oxide Thin Film.  

National Technical Information Service (NTIS)

To summarize, polycrystalline ZnO thin films were grown by reactive sputtering. Nitrogen was introduced into the films by reactive sputtering in an NO(sub 2) plasma or by N(sup+) implantation. All ZnO films grown show n-type conductivity. In unintentional...

S. X. Z. Li

2003-01-01

163

Thin film bioreactors in space.  

PubMed

Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers us an opportunity to learn more about basic biological systems with one important variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would enable us to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology. PMID:11537324

Hughes-Fulford, M; Scheld, H W

1989-01-01

164

Thin Film Charged Particle Detector  

NASA Astrophysics Data System (ADS)

Current charged particle detectors such as silicon barrierdetectors are unable to operate at high temperatures or in a high radiation background. It is possible to construct a new type of charged particle detector that does not suffer from these restrictions. This involves the stacking of several alternating conducting and insulating layers. It is then possible to estimate the number of charged particles that stop in any given conducting layer and hence the particle energy by measuring the current from the layer. Detectors based on this design have been built and tested with promising results. A new detector is currently under construction that would greatly reduce its size. This new detector is constructed by successively depositing thin films of nickel and alumina on a macor substrate. The linear particle accelerator, located at the Colorado School of Mines, will used to evaluate this new design.

Roy, Brian A.; Cecil, Ed

1998-04-01

165

Nanostructured Ni 3Sn 2 thin film as anodes for thin film rechargeable lithium batteries  

Microsoft Academic Search

Thin film Ni3Sn2 anodes were deposited on a Cu substrate by e-beam evaporator at room temperature. The deposited films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). They were tested as anodes for thin film rechargeable lithium batteries. These film electrodes exhibited an excellent cycle performance over 500 cycles. Ni3Sn2 films remained without undergoing any crystallographic phase

Young-Lae Kim; Heon-Young Lee; Serk-Won Jang; Seung-Joo Lee; Hong-Koo Baik; Young-Soo Yoon; Young-Shin Park; Sung-Man Lee

2003-01-01

166

Tungsten nanostructured thin films obtained via HFCVD  

NASA Astrophysics Data System (ADS)

By using the Hot Filament Chemical Vapor Deposition (HFCVD) technique tungsten thin films were deposited on amorphous quartz substrates. To achieve this, a tungsten filament was heated at 1300 °C during 30 minutes maintaining a constant pressure inside the chamber at 460 mTorr and substrate at 700 °C. Transition from tungsten oxide deposits to tungsten thin films, by varying the substrate temperature, were characterized by means of Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM), X-Ray Diffraction and, micro-Raman spectroscopy. The SEM micrographs reveal that the tungsten films have no more than 200 nm in thickness while XRD show evidence of the films crystallize in the ?-tungsten modification. On the other hand, AFM shows that the tungsten thin films exhibit a uniform and smooth surface composed with semi-spherical shapes whose diameters are below than 50 nm. Furthermore, to the naked eye, the as-deposited tungsten films exhibit a high mirror-like appearance.

Goiz, O.; Chávez, F.; Zaca-Morán, P.; Ortega-Mendoza, J. G.; Pérez-Sánchez, G. F.; Morales, N.; Felipe, C.; Peña-Sierra, R.

2011-09-01

167

Fabrication and characterization of PDMS thin film  

NASA Astrophysics Data System (ADS)

Because PDMS is viscous, it's impossible to form thin films of PDMS using spin coating without dilute it with solvents. We examine the optimal solvents and spin parameters for spin-coating the PDMS elastomer on glass substrates. Chloroform, Benzene, and Toluene have been attempted to study the influences of solvent on forming thin films of high uniformity. The experiments conclude: the solvent with lower evaporation rate produces more uniform films. No strong relationship between spin speeds and film uniformity has been observed when spin speed is high. However, the film uniformity begins to decline when lower spin speed is used. In addition, we find that the refractive index of the thin film can be modified by curing temperature.

Wang, Shuping; Kallur, Ajay; Goshu, Abeselom

2011-02-01

168

Synthesis of periodic mesoporous silica thin films  

SciTech Connect

We have synthesized periodic mesoporous silica thin films from homogeneous solutions. To synthesize the films, a thin layer of a pH 7 micellar coating solution that contains TMOS (tetramethoxysilane) is dip or spin-coated onto Si wafers, borosilicate glass, or quartz substrates. NH3 gas is diffused into the solution and causes rapid hydrolysis and condensation of the TMOS and the formation of periodic mesoporous thin films within 10 seconds. Combination of homogenous solutions and rapid product formation maximizes the concentration of the desired product and provides a controlled, predictable microstructure. The films have been made continuous and crack-free by optimizing initial silica concentration and film thickness. The films are being evaluated as high surface area, size-selective coatings for surface acoustic wave (SAW) sensors.

Anderson, M.T.; Martin, J.E.; Odinek, J.G.; Newcomer, P.

1996-06-01

169

Macro stress mapping on thin film buckling  

SciTech Connect

Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of thin film buckling in the case of compressive stresses. Since the 80's, a lot of theoretical work has been done to develop mechanical models but only a few experimental work has been done on this subject to support these theoretical approaches and nothing concerning local stress measurement mainly because of the small dimension of the buckling (few 10th mm). This paper deals with the application of micro beam X-ray diffraction available on synchrotron radiation sources for stress mapping analysis of gold thin film buckling.

Goudeau, P.; Villain, P.; Renault, P.-O.; Tamura, N.; Celestre, R.S.; Padmore, H.A.

2002-11-06

170

Structural characterization of thin film photonic crystals  

SciTech Connect

We quantitatively analyze the structure of thin film inverse-opal photonic crystals composed of ordered arrays of air pores in a background of titania. Ordering of the sphere template and introduction of the titania background were performed simultaneously in the thin film photonic crystals. Nondestructive optical measurements of backfilling with high refractive index liquids, angle-resolved reflectivity, and optical spectroscopy were combined with band-structure calculations. The analysis reveals a thin film photonic crystal structure with a very high filling fraction (92{endash}94%) of air and a substantial compression along the c axis ({similar_to}22{endash}25%).

Subramania, G.; Biswas, R.; Constant, K.; Sigalas, M. M.; Ho, K. M.

2001-06-15

171

Permanent laser conditioning of thin film optical materials  

DOEpatents

The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold. 9 figs.

Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

1995-12-05

172

Permanent laser conditioning of thin film optical materials  

DOEpatents

The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold.

Wolfe, C. Robert (Palo Alto, CA); Kozlowski, Mark R. (Pleasanton, CA); Campbell, John H. (Livermore, CA); Staggs, Michael (Tracy, CA); Rainer, Frank (Livermore, CA)

1995-01-01

173

Permanent laser conditioning of thin film optical materials  

DOEpatents

The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold.

Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

1990-10-15

174

Passivation Effects in Copper Thin Films  

SciTech Connect

We studied the influence of a 10 nm AlxOy passivation on the stress-temperature behavior of 100 nm and 1 {mu}m thick Cu films. At low temperatures, the passivation induces a large tensile stress increase in the 100 nm film; however, its effect on the 1 {mu}m film is negligible. At high temperatures, the opposite behavior is observed; while the passivation does not change the 100 nm film behavior, it strengthens the 1 {mu}m film by driving it deeper into compression. These observations are explained in light of a combination of constrained diffusional creep and dislocation dynamics unique to ultra-thin films.

Wiederhirn, G.; Nucci, J.; Richter, G.; Arzt, E. [Max Planck Institute for Metals Research, Heisenbergstr. 3, D-70569 Stuttgart (Germany); Balk, T. J. [University of Kentucky, Department of Chemical and Materials Engineering, 177 F. Paul Anderson Tower, Lexington, KY 40506-0046 (United States); Dehm, G. [Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstr. 12, A-8700 Leoben (Austria); Department Materials Physics, University of Leoben, Jahnstr. 12, A-8700 Leoben (Austria)

2006-02-07

175

Chemical Vapor Deposition of Thin Film Dielectrics.  

National Technical Information Service (NTIS)

Chemical vapor deposition (CVD) utilizing the reaction of tetraisopropyl titanate in an oxidizing atmosphere containing water vapor forms a thin film of TiO2 with the desirable dielectric properties. CVD yields the widest range of technological possibilit...

D. R. Harbison H. L. Taylor

1968-01-01

176

Optoelectronic Nanocomposite Materials for Thin Film Photovoltaics.  

National Technical Information Service (NTIS)

Final results are described for a seed project focusing on the development of inorganic, nanostructured semiconductor based composite thin films intended for use as heterojunction elements or photoactive contact materials for photovoltaic energy conversio...

J. B. Potter

2012-01-01

177

Rechargeable thin-film lithium batteries.  

National Technical Information Service (NTIS)

Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have recently been developed. The batteries, which are typically less than 6-(mu)m thick, can be fabri...

J. B. Bates G. R. Gruzalski N. J. Dudney C. F. Luck X. Yu

1993-01-01

178

Thin Films Formed by Electrochemical Reactions.  

National Technical Information Service (NTIS)

Reactively sputtered thin films of tantalum oxide deposited onto thermally oxidized silicon offer a very wide range of sheet resistivities. The application of an external d-c bias to the substrate during sputtering alters sheet resistivity with no change ...

C. D. Orr

1965-01-01

179

Method for thin film thermoelectric module fabrication  

US Patent & Trademark Office Database

Methods of fabrication of a thermoelectric module from thin film thermoelectric material are disclosed. In general, a thin film thermoelectric module is fabricated by first forming an N-type thin film thermoelectric material layer and one or more metallization layers on a substrate. The one or more metallization layers and the N-type thin film thermoelectric material layer are etched to form a number of N-type thermoelectric material legs. A first electrode assembly is then bonded to a first portion of the N-type thermoelectric material legs, and the first electrode assembly including the first portion of the N-type thermoelectric material legs is removed from the substrate. In a similar manner, a second electrode assembly is bonded to a first portion of a number of P-type thermoelectric material legs. The first and second electrode assemblies are then bonded using a flip-chip bonding process to complete the fabrication of the thermoelectric module.

2012-07-10

180

Thin film production method and apparatus  

DOEpatents

A method for forming a thin film material which comprises depositing solid particles from a flowing suspension or aerosol onto a filter and next adhering the solid particles to a second substrate using an adhesive.

Loutfy, Raouf O. (Tucson, AZ); Moravsky, Alexander P. (Tucson, AZ); Hassen, Charles N. (Tucson, AZ)

2010-08-10

181

Transparent Conducting Thin Films for Spacecraft Applications.  

National Technical Information Service (NTIS)

Transparent conductive thin films are required for a variety of optoelectronic applications: automotive and aircraft windows, and solar cells for space applications. Transparent conductive coatings of indium-tin-oxide (ITO)-magnesium fluoride (MgF2) and a...

M. E. Perez-davis T. Malave-sanabria P. Hambourger S. K. Rutledge D. Roig

1994-01-01

182

Characterization of lithium phosphorous oxynitride thin films.  

National Technical Information Service (NTIS)

Electrical and electrochemical properties of an amorphous thin-film lithium electrolyte, lithium phosphorous oxynitride (Lipon), have been studied with emphasis on the stability window vs Li metal and the behavior of the Li/Lipon interface. Ion conductivi...

X. Yu J. B. Bates G. E. Jellison

1996-01-01

183

Chemically deposited semiconducting molybdenum sulfide thin films  

SciTech Connect

The authors report the morphological, structural, optical, and electrical properties of molybdenum sulfide thin films deposited for the first time on a glass substrate by a simple chemical method using molybdenum (VI) ions, ammonia, hydrazine hydrate, and thioacetamide.

Mandal, K.C. (Tata Institute of Fundamental Research, Bombay (India)); Mondal, A. (Jadavpur Univ., Calcutta (India))

1990-03-01

184

Electrostatic Discharge Effects on Thin Film Resistors.  

National Technical Information Service (NTIS)

Recently, open circuit failures of individual elements in thin film resistor networks have been attributed to electrostatic discharge (ESD) effects. This paper will discuss the investigation that came to this conclusion and subsequent experimentation inte...

M. J. Sampson S. M. Hull

1999-01-01

185

Interaction of Thin Erbium Films with Aluminum.  

National Technical Information Service (NTIS)

Aluminum is a potential substrate to support thin erbium films used for high-temperature, hydrogen isotope storage. Both aluminum and erbium are reactive metals, and the interaction of the two could make for an unstable combination at elevated temperature...

J. M. Harris E. P. Boespflug D. M. Holloway J. L. Provo

1984-01-01

186

Highly transparent solution processed In-Ga-Zn oxide thin films and thin film transistors  

Microsoft Academic Search

Highly transparent In-Ga-Zn oxide (IGZO) thin films were fabricated by spin coating using acetate- and chlorate-based precursors,\\u000a and thin film transistors (TFTs) were further fabricated employing these IGZO films as the active channel layer. The impact\\u000a of the post-annealing temperature on the physical properties of IGZO films and performance of IGZO TFTs were investigated.\\u000a Compared to the nitrate-based IGZO precursor,

Y. Wang; S. W. Liu; X. W. Sun; J. L. Zhao; G. K. L. Goh; Q. V. Vu; H. Y. Yu

2010-01-01

187

Epitaxial thin-film Si solar cells  

Microsoft Academic Search

Most types of thin-film solar cells imply a radical departure from the dominant bulk crystalline Si technology. This is not the case for epitaxial thin-film solar cells. In this technology, a high quality Si layer is deposited epitaxially on a low-cost Si substrate (e.g. cast Upgraded Metallurgical Grade silicon or high-throughput Si ribbons) and processed into a solar cell. This

G. Beaucarne; F. Duerinckx; I. Kuzma; K. Van Nieuwenhuysen; H. J. Kim; J. Poortmans

2006-01-01

188

Integrated thin-film solar power system  

Microsoft Academic Search

The need for small and lightweight modular power systems is growing rapidly as the space science community continues to move toward smaller and less costly spacecraft (e.g., nanosatellites). Thus the use of lightweight thin-film photovoltaic solar cell arrays for power generation is an attractive possibility. Thin-film lithium ion energy storage with its large power densities and long cycling lifetimes should

R. P. Raffaelle; J. D. Harris; D. Hehemann; D. Scheiman; G. Rybicki; A. F. Hepp

2000-01-01

189

Surface, interface and thin-film magnetism  

SciTech Connect

In the last quarter of the 20th century, with the information revolution and the ever growing need to acquire, store, and retrieve information, the science and technologies attached to magnetic recording have experienced an explosive growth. Central to those pursuits has been the materials science of magnetism as it applies to surfaces, interfaces, and thin films. This report discusses topics on thin-film magnetism such as: theory, physical effects, prospects, opportunities and future developments. (JL)

Falicov, L.M. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Physics)

1991-07-01

190

Sculptured thin films — II. Experiments and applications  

Microsoft Academic Search

A report on the preparation and potential applications of sculptured thin films (STFs) is presented. STFs are nano-engineered\\u000a columnar thin films in which the columnar direction can made to change easily and often during growth. STFs of virtually any\\u000a material can be prepared through directional vapor deposition onto any surface under low adatom-mobility conditions. Columnar\\u000a shapes, such as zig-zag, C-,

R. Messier; Akhlesh Lakhtakia

1999-01-01

191

Ultrasonic Spraying Thin Films of Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

Carbon nanotubes have many interesting and useful properties, especially in terms of strength and electrical conductivity. However, they can be hard to work with because they are held together in bundles by strong Van der Waals forces. Much work has been performed in the ultrasonic spraying of liquid suspensions of single and multi-wall carbon nanotubes. The resulting thin films have a variety of applications, including electron transport in thin film photovoltaics.

Willey, Anthony; Davis, Robert; Vanfleet, Richard; Balls, Amy; Abbott, Jonathan

2011-10-01

192

Micro-sensor thin-film anemometer  

Microsoft Academic Search

A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14 deg half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward

Mark Sheplak; Catherine B. McGinley; Eric F. Spina; Ralph M. Stephens; Purnell Hopson Jr.; Vincent B. Cruz

1994-01-01

193

Combinatorial discovery of new thin film photovoltaics  

Microsoft Academic Search

A combinatorial approach to discover new types of thin film photovoltaic devices containing only abundant, inexpensive, and relatively nontoxic elements is described. A large number of compound semiconductors with band-gaps suitable for solar energy conversion (1.0-2.0 eV) are known, including many sulfide compounds, but have not yet been used in efficient devices. Thin films of several sulfide semiconductors will be

Joel A. Haber; Nathan J. Gerein; Timothy D. Hatchard; Matthieu Y. Versavel

2005-01-01

194

Amorphous and Thin-Film Silicon  

SciTech Connect

This paper outlines the key concepts set forth in the Amorphous and Thin-Film Silicon session at the National Center for Photovoltaics and Solar Program Review Meeting held March 26, 2003 in Denver, Colorado. Key elements of discussion centered around benchmarking the NREL/NCPV amorphous and thin-film silicon program, identifying holes in the scientific understanding of these materials and devices, identifying hurdles to large scale manufacturing, and what direction the program should take for future activities.

Nelson, B. P.; Atwater, H. A.; von Roedern, B.; Yang, J.; Sims, P.; Deng, X.; Dalal, V.; Carlson, D.; Wang, T.

2003-05-01

195

Modeling for mechanical behavior of thin films  

NASA Astrophysics Data System (ADS)

Two integrated computational-experimental methods capable of characterizing nonlinear stress-strain behavior of thin films or coatings are presented. The first method combines Finite Element simulation with Micro-Plane-Strain Compression experimental data for automotive paints (FE-MPSC) to self-consistently characterize the deformation resistance of thin films. A microscopic plane-strain compression apparatus constructed in DuPont Marshall R & D Laboratory by micro-fabrication technology was used to measure the force-displacement relationship of the thin film. Starting with an initial approximation of stress-strain curve assuming a uniform deformation field in the film, the correct stress-strain relationship of the film corresponding to the actual deformation field can be determined by iterative updating in the finite-element simulation. This method can circumvent the over-estimation of uniaxial stress-strain curve based on traditional methods which assume uniform deformation, uniform contact stress profile and ignore the effect of hydrostatic pressure. The second method, similarly, combines Finite Element simulation with Continuous Spherical Indentation experimental data (FE-CSI) to self-consistently characterize the deformation resistance of thin films. FE-CSI method has been applied to both macro-spherical indentation of SAE4340 steel disk and micro-spherical indentation of silicon thin film. Germane features are discussed, concluding remarks are drawn, and future research works are recommended.

Zhao, Fuzhang

196

Thin-Film Nanocapacitor and Its Characterization  

ERIC Educational Resources Information Center

|An undergraduate thin-film nanotechnology laboratory was designed. Nanocapacitors were fabricated on silicon substrates by sputter deposition. A mask was designed to form the shape of the capacitor and its electrodes. Thin metal layers of Au with a 80 nm thickness were deposited and used as two infinitely large parallel plates for a capacitor.…

Hunter, David N.; Pickering, Shawn L.; Jia, Dongdong

2007-01-01

197

Thermodynamical fluctuations and critical behavior in weakly disordered YBCO thin and ultrathin films  

NASA Astrophysics Data System (ADS)

The specific role of disorder in the transport properties of YBCO has been investigated, using both light-ion irradiation of thin films to finely tune the amount of atomic disorder, and ultra-thin films grown to study possible dimensional effects. For weak disorder, the samples display a resistive transition typical of the mean-field paraconductive regime of an homogeneous media, well described by the Lawrence and Doniach model for layered superconductors. As the disorder increases, two effects take place. First, the c-axis coherence length becomes shorter, leading to a more anisotropic material, as shown by the excess conductivity above Tc. Second, an incipient granularity is revealed, leading to a less sharper transition, which is analyzed within the random 3D XY critical model for the paracoherence transition. Two main results are derived: and experimental test of the Ginzburg criteria for the paracoherence transition, and a new fluctuation regime in a nanometric grain size superconductors.

Lesueur, Jerome; Degoy, S.; Aprili, Marco; Chambonnet, D.; Keller, D.

1996-07-01

198

Stress and grain growth in thin films  

Microsoft Academic Search

The mechanical properties of polycrystalline thin films with thickness of 1 ?m or less depend strongly on the grain geometry, the grain size, and the way in which the crystallographic orientations of the grains are distributed. Grain growth during film formation or during post-deposition annealing can play a dominant role in defining these microstructural characteristics, and therefore, the mechanical properties

Carl V. Thompson; Roland Carel

1996-01-01

199

Vacuum properties of palladium thin film coatings  

Microsoft Academic Search

A recent development, carried out at CERN for particle accelerator applications, showed that a vacuum chamber coated with a thin getter film and then exposed to ambient air may be transformed into a pump by “in situ” heating at temperatures as low as 180°C.Heating activates the diffusion into the film of the oxygen present in the surface passivation layer. Repeated

C. Benvenuti; P. Chiggiato; F. Cicoira; Y. L’Aminot; V. Ruzinov

2004-01-01

200

Infrared transparent carbon nanotube thin films  

Microsoft Academic Search

We have measured the infrared properties of optically transparent and electrically conductive single walled carbon nanotube thin films. We found that nanotube films with sheet resistance values of 200 Ω\\/sq show outstanding transmittance in the infrared range up to at least 22 ?m, with an average transmittance greater than 90% over this range. The infrared properties of various materials were

Liangbing Hu; David S. Hecht

2009-01-01

201

Infrared transparent carbon nanotube thin films  

Microsoft Academic Search

We have measured the infrared properties of optically transparent and electrically conductive single walled carbon nanotube thin films. We found that nanotube films with sheet resistance values of 200 Omega\\/sq show outstanding transmittance in the infrared range up to at least 22 mum, with an average transmittance greater than 90% over this range. The infrared properties of various materials were

Liangbing Hu; David S. Hecht; George Grüner

2009-01-01

202

Bimodal swelling responses in microgel thin films.  

PubMed

A series of studies on microgel thin films is described, wherein quartz crystal microgravimetry (QCM), surface plasmon resonance (SPR), and atomic force microscopy (AFM) have been used to probe the properties of microstructured polymer thin films as a function of film architecture and solution pH. Thin films composed of pNIPAm-co-AAc microgels were constructed by using spin-coating layer-by-layer (scLbL) assembly with poly(allylamine hydrochloride) (PAH) as a polycationic "glue". Our findings suggest that the interaction between the negatively charged microgels and the positively charged PAH has a significant impact on the pH responsivity of the film. These effects are observable in both the optical and mechanical behaviors of the films. The most significant changes in behavior are observed when the motional resistance of a quartz oscillator is monitored via QCM experiments. Slight changes to the film architecture and alternating the pH of the environment significantly changes the QCM and SPR responses, suggesting a pH-dependent swelling that is dependent on both particle swelling and polyelectrolyte de-complexation. Together, these studies allow for a deeper understanding of the morphological changes that take place in environmentally responsive microgel-based thin films. PMID:17407344

Sorrell, Courtney D; Lyon, L Andrew

2007-04-04

203

Ternary Compound Thin Film Solar Cells.  

National Technical Information Service (NTIS)

This research program is directed toward the growth and characterization of I-III-V1 sub 2 ternary compound thin films and the use of these films in the development of photovoltaic devices for terrestrial application. The materials under investigation are...

L. L. Kazmerski

1976-01-01

204

Improved Thin-Film Solar Cells.  

National Technical Information Service (NTIS)

During this contract thin-film GaAs solar cells using semitransparent Pt layers as the barrier contact have been made and investigated to improve their photovoltaic characteristics. Studies of the GaAs film, grown by the close-spaced oxide transport proce...

D. M. Perkins W. L. Hui G. Noel E. F. Pasierb

1966-01-01

205

Large grain gallium arsenide thin films  

SciTech Connect

Polycrystalline gallium arsenide films deposited on tungsten/graphite substrates have been used for the fabrication of thin film solar cells. Gallium arsenide films deposited on foreign substrates of 10 ..mu..m or less thickness exhibit, in most cases, pronounced shunting effects due to grain boundaries. MOS solar cells of 9 cm/sup 2/ area with an AMI efficiency of 8.5% and p/sup +//n/n/sup +/ homojunction solar cells of 1 cm/sup 2/ area with an AM1 efficiency of 8.8% have been prepared. However, in order to further improve the conversion efficiency before the development of effective passivation techniques, gallium arsenide films with large and uniform grain structure are necessary. The large grain gallium arsenide films have been prepared by using the arsine treatment of a thin layer of molten gallium on the substrate surface and the recrystallized germanium films on tungsten/graphite as substrates.

Chu, S.S.; Chen, W.J.; Chu, T.L.; Firouzi, H.; Han, Y.X.; Wang, Q.H.

1984-05-01

206

Chalcopyrite thin film solar cells by electrodeposition  

Microsoft Academic Search

This paper reviews the state of the art in using electrodeposition to prepare chalcopyrite absorber layers in thin film solar cells. Most of the studies deal with the direct preparation of Cu(In,Ga)Se2 films, and show that the introduction of gallium in the films is now becoming possible from single bath containing all the elements. Electrodeposition can also be used to

D. Lincot; J. F. Guillemoles; S. Taunier; D. Guimard; J. Sicx-Kurdi; A. Chaumont; O. Roussel; O. Ramdani; C. Hubert; J. P. Fauvarque; N. Bodereau; L. Parissi; P. Panheleux; P. Fanouillere; N. Naghavi; P. P. Grand; M. Benfarah; P. Mogensen; O. Kerrec

2004-01-01

207

Microcrystalline organic thin-film solar cells.  

PubMed

Microcrystalline organic films with tunable thickness are produced directly on an indium-tin-oxide substrate, by crystallizing a thin amorphous rubrene film followed by its use as a template for subsequent homoepitaxial growth. These films, with exciton diffusion lengths exceeding 200 nm, produce solar cells with increasing photocurrents at thicknesses up to 400 nm with a fill factor >65%, demonstrating significant potential for microcrystalline organic electronic devices. PMID:23939936

Verreet, Bregt; Heremans, Paul; Stesmans, Andre; Rand, Barry P

2013-08-13

208

Knudsen diffusion through thin fibrous films  

NASA Astrophysics Data System (ADS)

Variational upper and multiple scattering lower bounds on the Knudsen transport rates are applied to several slab geometries of finite thickness made up of parallel, randomly placed, overlapping long cylindrical fibers, one with fibers aligned perpendicular and a second with fibers parallel to the film edges. Estimates and rigorous error bounds are generated for various film thickness. Insight into collision paths useful for thin film vapor deposition, reactive matrix formation of composites, and gas membrane transport are obtained.

Li, Xiangning; Strieder, William C.

2007-06-01

209

Growth direction control YBCO thin films  

Microsoft Academic Search

The crystallographic orientation of thin films of Y1Ba2Cu3O7 (YBCO) on MgO and SrTiO3 was investigated with theta-2theta X-ray diffraction. The fraction of a-axis oriented material was measured as a function of substrate temperature during growth. Films prepared at substrate table temperatures yielding maximum Tc were purely c-axis oriented up to a critical film thichness (<= 5500 Å), above which also

F. Vassenden; G. Linker; J. Geerk

1991-01-01

210

Bistability in a superconducting Al thin film induced by arrays of Fe-nanodot magnetic vortices.  

PubMed

A hybrid system, consisting of an array of Fe nanodots covered by a superconducting Al thin film, exhibits very unusual magnetotransport, including a giant hysteretic magnetoresistance with different reversible or irreversible regimes related to the magnetic state of the array. These effects originate from the magnetic fields produced by magnetic nanodots in the "magnetic vortex state." This is a unique model system in which properties of a magnetic array are transferred into the superconductor. PMID:18233315

Villegas, J E; Li, C-P; Schuller, Ivan K

2007-11-28

211

Thin film absorber for a solar collector  

DOEpatents

This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

Wilhelm, William G. (Cutchogue, NY)

1985-01-01

212

Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films  

SciTech Connect

A method for preparing aerogel thin films by an ambient-pressure, continuous process is disclosed. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

Brinker, C.J.; Prakash, S.S.

1999-09-07

213

Method for making thin polypropylene film  

DOEpatents

An economical method is provided for making uniform thickness polypropylene film as thin as 100 Angstroms. A solution of polypropylene dissolved in xylene is formed by mixing granular polypropylene and xylene together in a flask at an elevated temperature. A substrate, such as a glass plate or microscope slide is immersed in the solution. When the glass plate is withdrawn from the solution at a uniform rate, a thin polypropylene film forms on a flat surface area of the glass plate as the result of xylene evaporation. The actual thickness of the polypropylene film is functional of the polypropylene in xylene solution concentration, and the particular withdrawal rate of the glass plate from the solution. After formation, the thin polypropylene film is floated from the glass plate onto the surface of water, from which it is picked up with a wire hoop.

Behymer, R.D.; Scholten, J.A.

1985-11-21

214

Magnetoresistivity of thin films of the electron-doped high-{ital T}{sub {ital c}} superconductor Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4{plus_minus}{delta}}  

SciTech Connect

We report measurements of the magnetoresistance of Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4{plus_minus}{delta}} epitaxial thin films with varying oxygen content in magnetic fields {ital H} applied parallel ({ital H}{parallel}{ital c}) and perpendicular ({ital H}{perpendicular}{ital c}) to the tetragonal {ital c} axis. We have observed critical scaling of the electrical resistivity that is consistent with a vortex-glass transition for a film with an optimum superconducting transition temperature {ital T}{sub {ital c}} of {approx_equal}22 K and {ital H}{parallel}{ital c}. The values of the zero-temperature upper critical field {ital H}{sub {ital c}{sub 2}}(0)=80 kOe and the in-plane zero-temperature coherence length {xi}{sub {ital ab}}(0)=64 A were obtained from an analysis of the fluctuation conductivity. For an overoxygenated film with {ital T}{sub {ital c}}{approx_equal}10 K, an anomaly develops with increasing field for {ital H}{parallel}{ital c} and {ital T}{approx_lt}2 K that is characterized by a minimum in the temperature dependence of the resistivity followed by a second resistive transition at a lower temperature, which is nearly independent of {ital H}. This behavior is similar to that previously observed in Nd{sub 2{minus}{ital x}}Ce{sub {ital x}}CuO{sub 4{minus}{delta}} single crystals and may be associated with the magnetic ordering of the Nd{sup 3+} ions. {copyright} {ital 1996 The American Physical Society.}

Herrmann, J.; de Andrade, M.C.; Almasan, C.C.; Dickey, R.P.; Maple, M.B. [Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, California 92093-0360 (United States); Jiang, W.; Mao, S.N.; Greene, R.L. [Center for Superconductivity Research, University of Maryland, College Park, Maryland 20742 (United States)

1996-08-01

215

Solvent-induced morphology changes in thin silver films  

Microsoft Academic Search

Thin Ag films supported on dielectric materials have been extremely popular as surface-enhanced Raman scattering (SERS) substrates. In an effort to characterize SERS-active films under the conditions of typical SERS experiments, we have extended our previous work to elucidate the effect of solvent exposure on thin Ag film optical properties and surface morphology. When thin Ag films are dipped in

Shane E. Roark; David J. Semin; Alan Lo; Rex T. Skodje; Kathy L. Rowlen

1995-01-01

216

Effect of surface layers on ferromagnetic resonance in thin Fe films: Ni, Co, Si, and YBa2Cu3O7??  

Microsoft Academic Search

The results of ferromagnetic resonance experiments on 10 nm polycrystalline films of Fe with very thin surface layers of Ni and Co, using Si and a high temperature superconductor (YBCO) as substrates is reported herein. An earlier fmr investigation of Fe films on YBCO showed strongly temperature dependent linewidths and resonance fields but only small effects in Fe on Si.

P. Lubitz; M. Rubinstein; D. B. Chrisey; J. S. Horwitz; P. R. Broussard

1994-01-01

217

Electrochemical Analysis of Conducting Polymer Thin Films  

PubMed Central

Polyelectrolyte multilayers built via the layer-by-layer (LbL) method has been one of the most promising systems in the field of materials science. Layered structures can be constructed by the adsorption of various polyelectrolyte species onto the surface of a solid or liquid material by means of electrostatic interaction. The thickness of the adsorbed layers can be tuned precisely in the nanometer range. Stable, semiconducting thin films are interesting research subjects. We use a conducting polymer, poly(p-phenylene vinylene) (PPV), in the preparation of a stable thin film via the LbL method. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize the ionic conductivity of the PPV multilayer films. The ionic conductivity of the films has been found to be dependent on the polymerization temperature. The film conductivity can be fitted to a modified Randle’s circuit. The circuit equivalent calculations are performed to provide the diffusion coefficient values.

Vyas, Ritesh N.; Wang, Bin

2010-01-01

218

Adhesive Transfer of Thin Viscoelastic Films  

NASA Astrophysics Data System (ADS)

Micellar suspensions of acrylic diblock copolymers are excellent model materials for studying the adhesive transfer of viscoelastic solids. The micellar structure is maintained in films with a variety of thicknesses, giving films with a well-defined structure and viscoelastic character. Thin films were cast onto elastomeric silicone substrates from micellar suspensions in butanol, and the adhesive interactions between these coated elastomeric substrates and a rigid indenter were quantified. By controlling the adhesive properties of the film/indenter and film/substrate interfaces we were able to obtain very clean transfer of the film from the substrate to the portion of the glass indenter with which the film was in contact. Adhesive failure at the film/substrate begins with the nucleation of a cavity at the film/substrate interface, followed by complete delamination of this interface. The final stage in the transfer process involves the failure of the film that bridges the indenter and the elastomeric substrate at the periphery of the contact area. This film is remarkably robust, and is extended to three times its original length prior to failure. Failure of this film occurs at the periphery of the indenter, giving a transferred film that conforms to the original contact area between the indenter and the coated substrate.

Shull, Kenneth

2005-03-01

219

Mirrorlike pulsed laser deposited tungsten thin film.  

PubMed

Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10(-5) Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ?782 nm. PMID:21280810

Mostako, A T T; Rao, C V S; Khare, Alika

2011-01-01

220

Plasma Effects on Thin Copper Films  

NASA Astrophysics Data System (ADS)

The effects of low energy plasma bombardment have been quantified for the first time. The plasma effects on thin copper films (~50 nm) have been studied by exposing these films to Magnetically Enhanced (ME) Ar plasmas. The Cu films deposited on strips of membrane wafers were exposed to plasmas by systematically varying the exposure time and the RF power. The microstructural changes and the surface morphology of the films were studied using Transmission Electron and Atomic Force Microscopies (TEM, AFM). AFM was found to be the most sensitive technique to study the film morphology. The membrane wafer approach required no sample preparation and the changes observed are entirely due to plasma processing. The ion impingement energies were simulated from the ion density data collected by Langmuir probe and the substrate DC bias. The TEM sample temperature was estimated by heat transfer calculations using the experimental data. Grain growth is observed in thin Cu films when the films are exposed to low energy ME Ar plasmas. The gas pressure in the plasma reactor and the RF power are shown to have a strong influence on the microstructure of Cu films. The microstructural changes in sputtered and evaporated films are quite significant whereas the plasma bombardment has less effect on CVD films. These changes occur very rapidly and cannot be attributed solely to the thermal effects especially at low RF powers (300 to 500 W). The effect of temperature, however, becomes significant at 700 W. AFM observations suggest the grain boundary grooving to be the initiating mechanism for grain growth. The curvature driven motion of grain boundary is initiated and the entire microstructure is affected due to the dimensional (2-D) aspect of the grain size of the film. The diffusion of a fraction of the near surface defects into bulk of the film via grain boundaries enhances the process. As seen in the case of CVD films, the initial microstructure of the film also plays a role in grain growth during plasma exposure.

Naeem, Munir-Ud-Din

1993-01-01

221

Superconductor to insulator transitions in amorphous nanohoneycomb films  

NASA Astrophysics Data System (ADS)

Two dimensional electronic systems exhibit a wide variety of phenomena including the quantum Hall effect, weak and strong localization, and metal-insulator transitions, including the superconductor to insulator transition (SIT). In each case the possibility of a universal explanation, independent of the microscopic details of the system, has tantalized researchers. In some cases, such as the temperature dependence of the conductance of metal films, or the spacing of resistance plateaus in the Hall effect, universal behavior is without doubt. Universal explanations of the amorphous film SIT revolve around the dirty Boson model, in which the sharp rise in the resistance of a film at low temperature is due to the localization of Cooper pairs. The existence of long-lived Cooper pairs in an electrically insulating system, the central assumption of the model, has remained in doubt because some measurements support the assertion and others refute it. This thesis addresses this experimental dissonance by investigating the SITs of amorphous Bismuth films perforated with a regular nanohoneycomb (NHC) array of holes. The nanoscale perforations allow a direct measurement of phase coherent Cooper pairs with an applied magnetic field. On the insulating side of the disorder driven SIT the resistance as a function of magnetic field oscillates with a period, h/2eS, where S is the area of a unit cell of holes. The 2e period betrays the presence of localized Cooper pairs in an electrically insulating state. The magnetoresistance of weak superconducting films reveals several SITs which qualitatively resemble the disorder driven SIT. The behavior of these transitions borrows heavily from both sides of a dichotomy exhibited by different materials through their field driven SITs. NHC films show activated resistances and a large peak in the magnetoresistance, analogous to the more spectacular behavior of some materials. However, they also show a very weak, almost metallic, temperature dependence for a range of fields near the SIT, not unlike the metallic phase of unpatterned Bismuth and other materials. These results suggest that an underlying multiply connected geometry in ostensibly amorphous, unpatterned films may account for some of the range of material dependent behavior.

Stewart, M. D., Jr.

222

Thin film dielectric composite materials  

DOEpatents

A dielectric composite material comprising at least two crystal phases of different components with TiO.sub.2 as a first component and a material selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is from 0.3 to 0.7, Pb.sub.1-x Ca.sub.x TiO.sub.3 where x is from 0.4 to 0.7, Sr.sub.1-x Pb.sub.x TiO.sub.3 where x is from 0.2 to 0.4, Ba.sub.1-x Cd.sub.x TiO.sub.3 where x is from 0.02 to 0.1, BaTi.sub.1-x Zr.sub.x O.sub.3 where x is from 0.2 to 0.3, BaTi.sub.1-x Sn.sub.x O.sub.3 where x is from 0.15 to 0.3, BaTi.sub.1-x Hf.sub.x O.sub.3 where x is from 0.24 to 0.3, Pb.sub.1-1.3x La.sub.x TiO.sub.3+0.2x where x is from 0.23 to 0.3, (BaTiO.sub.3).sub.x (PbFeo.sub.0.5 Nb.sub.0.5 O.sub.3).sub.1-x where x is from 0.75 to 0.9, (PbTiO.sub.3).sub.- (PbCo.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.1 to 0.45, (PbTiO.sub.3).sub.x (PbMg.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.2 to 0.4, and (PbTiO.sub.3).sub.x (PbFe.sub.0.5 Ta.sub.0.5 O.sub.3).sub.1-x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

Jia, Quanxi (Los Alamos, NM); Gibbons, Brady J. (Los Alamos, NM); Findikoglu, Alp T. (Los Alamos, NM); Park, Bae Ho (Los Alamos, NM)

2002-01-01

223

Critical currents of ion-beam sputtered amorphous beryllium thin films and their application to an Abrikosov vortex memory  

SciTech Connect

Critical current and flux pinning were examined for ion-beam sputtered (IBS)= amorphous beryllium (a-Be) thin films with T/sub c/ 6 K. Pinning forces in IBS a-Be films were one or more than one order of magnitude smaller than those for crystalline superconductors, but were still rather large for amorphous superconductors. The viscosity coefficient for IBS a-Be was very small, 1--2 x 10/sup -9/ N s/m/sup 2/, which was only a few tenths as large as viscosity coefficients for other metallic superconductors. Write operation characteristics for Abrikosov vortex memory with an IBS a-Be vortex storage region was tested. The write current level was reduced to about two thirds of that for fine-grained PbInAu previously reported. IBS a-Be films were proved to be a potential material for use in an Abrikosov vortex memory.

Okamoto, M.; Takei, K.; Kubo, S.; Mukaida, M.; Miyahara, K.

1987-07-01

224

Capillary stress in microporous thin films  

SciTech Connect

Development of capillary stress in porous xerogels, although ubiquitous, has not been systematically studied. The authors have used the beam bending technique to measure stress isotherms of microporous thin films prepared by a sol-gel route. The thin films were prepared on deformable silicon substrates which were then placed in a vacuum system. The automated measurement was carried out by monitoring the deflection of a laser reflected off the substrate while changing the overlying relative pressure of various solvents. The magnitude of the macroscopic bending stress was found to reach a value of 180 MPa at a relative pressure of methanol, P/Po = 0.001. The observed stress is determined by the pore size distribution and is an order of magnitude smaller in mesoporous thin films. Density Functional Theory (DFT) indicates that for the microporous materials, the stress at saturation is compressive and drops as the relative pressure is reduced.

Samuel, J.; Hurd, A.J.; Frink, L.J.D.; Swol, F. van [Sandia National Labs., Albuquerque, NM (United States); Brinker, C.J. [Sandia National Labs., Albuquerque, NM (United States). Ceramic Processing Science Dept.]|[Univ. of New Mexico, Albuquerque, NM (United States). Center for Micro Engineering Ceramics; Raman, N.K. [Univ. of New Mexico, Albuquerque, NM (United States). Center for Micro Engineered Ceramics

1996-06-01

225

A thin-film capacitive bolometer.  

PubMed

A thin-film capacitive bolometer is described, which depends on a temperature sensitivity derived from electron trapping effects in thin amorphous dielectric films containing an ionic space charge. The theory of thisprocess is summarized and shown to be in good agreement with results obtained from anodized Nb(2)O(5) capacitors. The capacitive elements can be formed on thin-film supportingstructures to achieve large thermal detectivities D*. An analysis given for an optimized detector indicatesthat it is possible to reach the theoretical maximum D* at room temperature. Experimental detectors aredescribed which were fabricated from anodized Nb(2)O(5) and evaporated Al(2)O-TiO(2) capacitors. Their performance at room temperature indicates responsivities of at least 2 mV/microW, effective time constants of about 0.05 sec, and D*'s in excess of 10(9). PMID:20076186

Maserjian, J

1970-02-01

226

Method for synthesizing thin film electrodes  

DOEpatents

A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.

Boyle, Timothy J. (Albuquerque, NM)

2007-03-13

227

Nanostructures in thin film opto-electronics  

NASA Astrophysics Data System (ADS)

Recent investigations in the area of photovoltaics and microelectronics generated interest in thin-film technologies with nanostructural modifications. In this paper we concentrate on technological experiments, structure and composition control of the components of a thin silicon solar cell and opto-electonic devices. The results of high resolution electron microscopy and optical transmission and reflection analysis are presented. Additionally, the authors carried out theoretical calculations of scattering, absorption and reflection of the Ag nanoparticles located at the surface and also within the films on the absorber border.

Ko?odziej, Andrzej; Jakubowski, Andrzej; Ko?odziej, Micha?

2013-07-01

228

Borocarbide thin films and tunneling measurements.  

SciTech Connect

The results obtained by their group in thin film fabrication and STM tunneling on superconducting borocarbides YNi{sub 2}B{sub 2}C have been be briefly reviewed. Results concerning the microwave surface impedance and the S/N planar junctions on LuNi{sub 2}B{sub 2}C thin films have been also presented and analyzed. These new data unambiguously confirm the full BCS nature of the superconducting gap in borocarbides and the absence of significant pair-breaking effects in LuNi{sub 2}B{sub 2}C.

Iavarone, M.; Andreone, A.; Cassinese, A.; Dicapual, R.; giannil, L.; Vagliol, R.; DeWilde, Y.; Crabtree, G. W.

2000-06-15

229

Interfacial Delamination of PZT Thin Films  

Microsoft Academic Search

\\u000a The interface strength of Pb(Zr,Ti)O3(PZT) thin films on a silicon substrate is studied experimentally and numerically in this work. First, a sandwiched cantilever\\u000a specimen is proposed to perform the delamination tests. The experimental results show that the multilayered Cr\\/PZT\\/PLT\\/Pt\\/Ti\\u000a thin films deposited on single-crystal silicon substrates are delaminated along the interface between Cr and PZT layers in\\u000a a brittle manner.

Fulin Shang; Yabin Yan; Takayuki Kitamura

230

Thin-Film Dielectrics for Microelectronics: A Bibliography Compilation.  

National Technical Information Service (NTIS)

The report was in response to a request for information on various thin-film dielectric materials used for making capacitive elements in microelectronics circuitry. Included are sections on the following: Thin film capacitors (general); Silicon monoxide f...

J. T. Milek

1968-01-01

231

Thin Film ZT Characterization using Transient Harman Technique.  

National Technical Information Service (NTIS)

Thin-film thermoelectric materials offer great potential for improving the thermoelectric figure of merit ZT due to the freedom of tailoring the electron and heat transport. The characterization of these thin films is difficult because of the coexistence ...

A. Shakouri H. Schmidt Z. Bian Z. Yan

2005-01-01

232

Thin Films in the Technology of Superhigh Frequencies.  

National Technical Information Service (NTIS)

A comprehensive discussion of the physics, manufacturing processes and applications of thin films in modern communications technology. The following subjects are discussed in detail: (1) Structure and properties of thin films: vacuum vaporization, cathode...

1971-01-01

233

Thin-Film Hybrid Microcircuit Wide-Band Noise Generator.  

National Technical Information Service (NTIS)

The knowledge and experience gained through previous fabrication and evaluation of thin-film components in the Electronic Components Laboratory is applied to an electronic circuit known as a 'wideband amplitude noise generator.' The thin-film noise genera...

R. A. Reitmeyer S. Firestone H. C. Frankel

1969-01-01

234

Tem characterization of nanodiamond thin films  

Microsoft Academic Search

The microstructure of thin films grown by microwave plasma-enhanced chemical vapor deposition (MPCVD) from fullerene C60 precursors has been characterized by scanning electron microscopy (SEM), selected-area electron diffraction (SAED), bright-field electron microscopy, high-resolution electron microscopy (HREM), and parallel electron energyloss spectroscopy (PEELS). The films are composed of nanosize crystallites of diamond, and no graphitic or amorphous phases were observed. The

L.-C. Qin; D. Zhou; A. R. Krauss; D. M. Gruen

1998-01-01

235

Polycrystalline silicon thin films on glass substrate  

Microsoft Academic Search

The formation of high-quality polycrystalline silicon (poly-Si) on low cost substrates has important applications in the development of thin film solar cells, transistors, image sensors, etc. In this study, we present the results of an investigation of poly-Si and poly-SiGe films on glass, formed by aluminum induced crystallization (AIC). The process is based on the isothermal annealing at temperatures between

D. Dimovamalinovska; O. Angelov; M. Sendova-Vassileva; M. Kamenova; J.-C. Pivin

2004-01-01

236

Elastic Properties of Amorphous Thin Films  

Microsoft Academic Search

In an attempt to gain a better understanding of the universal low temperature properties of amorphous solids, a technique has been developed for measuring the elastic properties of amorphous thin films. The technique has been applied to a study of electron beam evaporated amorphous SiO_2 films with thicknesses ranging from 0.75 nm to 1000 nm. We find that the anomalous

Bruce Edward White Jr.

1996-01-01

237

Heterogeneous Thin Films of Martensitic Materials  

Microsoft Academic Search

:  We study the effective behavior of heterogeneous thin films with three competing length scales: the film thickness and the\\u000a length scales of heterogeneity and material microstructure. We start with three-dimensional nonhomogeneous nonlinear elasticity\\u000a enhanced with an interfacial energy of the van der Waals type, and derive the effective energy density as all length scales\\u000a tend to zero with given limiting

Y. C. Shu

2000-01-01

238

Annealed CVD molybdenum thin film surface  

DOEpatents

Molybdenum thin films deposited by pyrolytic decomposition of Mo(CO).sub.6 attain, after anneal in a reducing atmosphere at temperatures greater than 700.degree. C., infrared reflectance values greater than reflectance of supersmooth bulk molybdenum. Black molybdenum films deposited under oxidizing conditions and annealed, when covered with an anti-reflecting coating, approach the ideal solar collector characteristic of visible light absorber and infrared energy reflector.

Carver, Gary E. (Tucson, AZ); Seraphin, Bernhard O. (Tucson, AZ)

1984-01-01

239

Autocorrelating femtosecond pulses with thin bacteriorhodopsin films  

NASA Astrophysics Data System (ADS)

A 10-?m thick electrophoretically sedimented film of bacteriorhodopsin (bR) was used, for the first time, to accurately measure width of 120-fs light pulses produced by a mode-locked Ti: sapphire laser. No Maker fringes structure was observed in the second harmonic generation pattern. The results show that thin films of bacteriorhodopsin have characteristics that are of considerable practical importance in femtosecond pulse characterization.

Bouevitch, Oleg; Lewis, Aaron

1995-02-01

240

Thin film thickness determination with neutron activation analysis.  

PubMed

Thickness determination of Ta2O5 thin films, deposited on the glass substrates and metallic indium and gold thin films on both glass and aluminum substrates, were performed by neutron activation analysis. Thickness determination of these thin films were made by comparing gamma-rays emitted from the radio-isotopes in the thin film with the substrate material followed by the neutron irradiations. The method led to determination of the film thicknesses without using any standard sample. A complementary optical transmission measurement was also applied on multi-layered Ta2O5 thin films for determining the individual layer densities. PMID:11339537

Ozben, C S; Tepehan, F Z; Güven, H H; Tepehan, G G

2001-07-01

241

The topography of iron oxide thin films (abstract)  

Microsoft Academic Search

The surface mophology of thin-film recording media is important for recording characteristics. STM analysis was done for iron oxide thin films prepared by a water vapor added rf-sputtering process.1 They were oxidized in an open air in the temperature range 300–350 °C in order to transfer magnetite thin films to gamma iron oxide thin films. The STM image of gamma

Zeng-Jun Zhou; Jun Jue Yan

1991-01-01

242

Kinematic and dynamic vortices in a thin film driven by an applied current and magnetic field  

NASA Astrophysics Data System (ADS)

Using a Ginzburg-Landau model, we study the vortex behavior of a rectangular thin film superconductor subjected to an applied current fed into a portion of the sides and an applied magnetic field directed orthogonal to the film. Through a center manifold reduction we develop a rigorous bifurcation theory for the appearance of periodic solutions in certain parameter regimes near the normal state. The leading order dynamics yield in particular a motion law for kinematic vortices moving up and down the center line of the sample. We also present computations that reveal the co-existence and periodic evolution of kinematic and magnetic vortices.

Peres Hari, Lydia; Rubinstein, Jacob; Sternberg, Peter

2013-10-01

243

Preface: Thin films of molecular organic materials  

NASA Astrophysics Data System (ADS)

This special issue is devoted to thin films of molecular organic materials and its aim is to assemble numerous different aspects of this topic in order to reach a wide scientific audience. Under the term 'thin films', structures with thicknesses spanning from one monolayer or less up to several micrometers are included. In order to narrow down this relaxed definition (how thin is thin?) I suggest joining the stream that makes a distinction according to the length scale involved, separating nanometer-thick films from micrometer-thick films. While the physical properties of micrometer-thick films tend to mimic those of bulk materials, in the low nanometer regime new structures (e.g., crystallographic and substrate-induced phases) and properties are found. However, one has to bear in mind that some properties of micrometer-thick films are really confined to the film/substrate interface (e.g. charge injection), and are thus of nanometer nature. Supported in this dimensionality framework, this issue covers the most ideal and model 0D case, a single molecule on a surface, through to the more application-oriented 3D case, placing special emphasis on the fascinating 2D domain that is monolayer assembly. Thus, many aspects will be reviewed, such as single molecules, self-organization, monolayer regime, chirality, growth, physical properties and applications. This issue has been intentionally restricted to small molecules, thus leaving out polymers and biomolecules, because for small molecules it is easier to establish structure--property relationships. Traditionally, the preparation of thin films of molecular organic materials has been considered as a secondary, lower-ranked part of the more general field of this class of materials. The coating of diverse surfaces such as silicon, inorganic and organic single crystals, chemically modified substrates, polymers, etc., with interesting molecules was driven by the potential applications of such molecular materials/substrate systems (also called heterostructures) based on the physical properties of the bulk materials, usually in the form of single crystals. However, in recent years the thin films community has been continually growing, helping the field to mature. In my opinion two main aspects have advanced the thin molecular films field. The first is the different applications with optical and electrical devices such as OFETs (organic field-effect transistors) and OLEDs (organic light emitting diodes), applications that could not have been achieved with single crystals because of limited size, difficult processability and mechanical fragility. The second is the involvement of the surface science community with their overwhelming arsenal of experimental techniques. From the synthesis point of view, the preparation of thin films is being regarded as a complementary synthesis route. The different externally accessible variables involved in the preparation process (temperature, pressure, molecular flux, distance, time, concentration, solvent, substrate, etc.), which define the so-called parameter hyperspace, can be so diverse when comparing competing synthesis routes (e.g. solution versus vapour growth) that we should not be surprised if different crystallographic phases with different morphologies are obtained, even if metastable. We should not forget here that the amazingly large number of available molecules is due to the longstanding and innovative work of synthesis chemists, a task that has not been sufficiently recognized (laymen in the domain of synthesis of organic molecules tend to believe that almost any molecule can be synthesized). In summary, one of the goals of this issue is to highlight the emerging importance of the field of thin molecular organic films by giving selected examples. It is clear that some important examples are missing, which are due in part to space limitation and to the understandable reluctance of highly-ranked specialists to contribute because of work overload. Among these not included but not forgotten subjects we can list films showing linear and non

Fraxedas, J.

2008-03-01

244

Violet and Blue Light Emissions from Nanocrystalline Silicon Thin Films  

Microsoft Academic Search

Nanocrystalline silicon thin films with a grain diameter from three to seven nanometers were fabricated on silicon substrates. It is demonstrated for the first time that the thin films show intense violet and blue luminescence at room temperature. The luminescence spectra include three peaks at wavelengths of 415 nm, 437 nm and 465 nm. Anodizations of these thin films introduce

Xinwei Zhao; Olaf Schoenfeld; Junichi Kusano; Yoshinobu Aoyagi; Takuo Sugano

1994-01-01

245

Biaxial Fatigue Testing of Thin Films  

NASA Astrophysics Data System (ADS)

A new experimental setup, which allows for testing in an equi-biaxial loading condition, has been developed and applied to investigate the fatigue behaviour of thin films. A load controlled cycling, performed at room temperature on flat specimens, reproduces the strain amplitude and mean strain in the film corresponding to a thermal cycling in a given temperature range. The setup is based on the ring-on-ring test, which has been successfully used in biaxial fracture testing of glass and ceramics, and includes an optical in-situ failure detection system. The method is validated for specimens consisting in a gold film deposited on a polymer substrate.

Eve, S.; Huber, N.; Ernst, E.; Last, A.; Schlagenhof, M.; Kraff, O.

2006-02-01

246

Physical aging of thin glassy polymer films  

NASA Astrophysics Data System (ADS)

This research work was designed to systematically investigate the physical aging of glassy polymer thin films in terms of the effects of chemical structure of the polymer, film thickness, aging temperature and molecular weight. This research is fundamental in nature but is of both scientific interest and practical importance, especially to gas separation industry where polymer thin films are essentially used as the selective layer in the asymmetric or composite membrane structures. Three glassy polymers relevant to gas separation industry, polysulfone, a polyimide and poly(2,6-dimethyl-1,4-phenylene oxide) were studied; these polymer films having thicknesses from ˜ 400 nm to 62 mum were subjected to isothermal aging at three temperatures, ranging from 35 to 55°C, for a period of up to ˜ 400 days. Two major techniques were employed in probing the aging process including gas permeability measurement and refractive index measurement. Rigorous methodologies have been developed for studying the physical aging of free-standing thin polymer films to eliminate any other external effect that might impact the aging behavior. Ellipsometry has been employed to determine the thicknesses and refractive indices of these thin films. By using the methods developed, the reproducibility of gas permeability and refractive index change during physical aging was demonstrated as well as the thermoreversibility of physical aging. Ellipsometry revealed that this procedure leads to isotropic films having initial characteristics independent of film thickness. A substantial aging response via the permeability and refractive index changes, attributed to a decrease in polymer free volume, was observed at temperatures more than 150°C below Tg for thin films of each polymer compared to what is observed for the bulk polymers. The Lorenz-Lorenz equation was used to relate changes in refractive index to densification, or volume relaxation, with aging time. The films with thicknesses of approximately 400 nm of the three polymers exhibit an oxygen permeability decrease by as much as two-fold or more, about 14 to 15% increase in O 2/N2 selectivity and about 0.6 to 1.5% increase in density at an aging time of 1,000 hours. (Abstract shortened by UMI.)

Huang, Yu

247

Thin Film Photovoltaic Cell Array Investigation.  

National Technical Information Service (NTIS)

Work has continued with the objective of showing the feasibility of fabricating a large area array segment in which individual cells are simultaneously interconnected by thin film techniques. The ohmic contact has proven to be the major obstacle to the ac...

R. S. Schlotterbeck

1966-01-01

248

Thin Film Photovoltaic Cell Array Investigation.  

National Technical Information Service (NTIS)

Single crystal CD/TE solar cells have been fabricated by procedures analogous to those employed with thin film cells. The effect of high temperature (125 C in helium) and 1.5 mev electron irradiation (5 x 10 to the 16th power/sq. cm) upon the spectral res...

R. S. Schlotterbeck

1966-01-01

249

PLD growth of thin film Zinc Phosphide  

NASA Astrophysics Data System (ADS)

The development of efficient, low cost solar cells to meet society's growing energy needs has triggered tremendous interest in developing photovoltaics formed from earth abundant materials. Zinc phosphide (Zn3P2) is a promising earth abundant absorber layer for photovoltaic energy conversion with a nearly ideal band gap (1.5eV) and a large absorption coefficient of 10^4/cm. In this work we examine the growth parameters, electrical and optical properties of thin film zinc phosphide produced using pulsed laser deposition (PLD) from a zinc phosphide target at laser fluencies ranging from 1-3 J/cm2. For the laser fluences explored, highly resistive amorphous zinc phosphide thin films were produced with a band gap of approximately 1.7 eV. The thin films could be transformed from amorphous to polycrystalline zinc phosphide by annealing at 400C for 15mins in a N2 atmosphere. High resolution X-ray photoelectron spectroscopy (XPS) is used to examine the binding energies of Zn 2p3/2 and Phosphorous 2p3/2 signals and are in the range of 1021.6 eV and 127.5 eV. Energy Dispersive X-ray Spectroscopy (EDAX) revealed that the Zn3P2 thin films are nearly stoichiometric in composition. Hall mobility in these materials and Zn3P2/ZnS hetrojunction solar cell performance will be discussed.

Vaddi, Rajesh; Vasekar, Parag; Westgate, Charles; White, Bruce

2013-03-01

250

Termination materials for thin film resistors  

Microsoft Academic Search

The resistance of a thin film resistor can be considered as consisting of three parts: 1) the resistance of the resistor material, 2) the resistance of the termination material, and 3) the interfacial resistance. The aging of the interfacial resistance can dominate the aging of low valued resistors, especially under corrosive conditions. The interfacial resistance using a distributed parameter analysis

JOHN S. FISHER; PETER M. HALL

1971-01-01

251

Microwave Magnetic Thin Film Soliton Device Physics.  

National Technical Information Service (NTIS)

ARO Grant DAAH04-95-1-0325 (P-33936-PH) has supported a research program to explore and implement concepts which utilize microwave magnetic envelope solitons in thin magnetic film device configurations for signal processing at microwave and millimeter wav...

C. E. Patton

1998-01-01

252

Digital thin-film color optical memory  

Microsoft Academic Search

A promising optical memory device called digital thin-film (DTF) color optical memory is presented. The DTF optical memory utilizes localized regions of varying thickness to adjust the spectral characteristic of reflected light from a broad band source. The DTF structure has been fabricated by Ga+ focused ion beam milling on thermally grown silicon dioxide on Si to prove the concept.

C. J. Chi; A. J. Steckl

2001-01-01

253

Thin film color sensors in multichannel technology  

Microsoft Academic Search

Color images are commonly captured with sensor arrays covered with a mosaic of RGB-filters. In spite of the enormous success of CMOS and CCD color cameras, one-chip color imagers suffer form color aliasing or color moire effects. In order to overcome these limitations we have realized color sensors based on vertical integrated thin film structures. The compete color information of

Dietmar Knipp; Helmut Stiebig; Heribert Wagner

2001-01-01

254

UV absorption control of thin film growth  

DOEpatents

A system for monitoring and controlling the rate of growth of thin films in an atmosphere of reactant gases measures the UV absorbance of the atmosphere and calculates the partial pressure of the gases. The flow of reactant gases is controlled in response to the partial pressure.

Biefeld, Robert M. (Albuquerque, NM); Hebner, Gregory A. (Albuquerque, NM); Killeen, Kevin P. (Albuquerque, NM); Zuhoski, Steven P. (Hopewell Junction, NY)

1991-01-01

255

Thin-Film-Transistor Stability Investigation.  

National Technical Information Service (NTIS)

This program was undertaken to identify the key parameters required for stable operation of thin-film transistors (TFTs), to define the range of stable operation, and to assess TFT-device reliability and yield. Lead sulfide (PbS) and lead selenide semicon...

G. Kramer

1975-01-01

256

Low temperature OMCVD of thin rhodium films.  

National Technical Information Service (NTIS)

Thin, highly reflective rhodium films with metal compositions greater than 98% (elemental weight percentage) have been deposited by chemical vapor deposition using Rh(allyl)(sub 3) (allyl = (eta)(sup 3)-C(sub 3)H(sub 5)) in the presence of a hydrogen plas...

J. R. Laia A. P. Sattelberger D. C. Smith J. C. DeSantis

1992-01-01

257

Anemometer with hot platinum thin film  

Microsoft Academic Search

The techniques of micromachining silicon are used for the manufacture of an anemometer with low electric consumption and great sensitivity. To reduce the energy consumption, a suspended membrane of silicon rich silicon nitride SiNx makes it possible to carry out the heat insulation between the heater and the substrate. Platinum (Pt) thin film (3000Å) with titanium (300Å) adhesion layer on

F Mailly; A Giani; R Bonnot; P Temple-Boyer; F Pascal-Delannoy; A Foucaran; A Boyer

2001-01-01

258

Thin Ferroelectric Films for Thermal Detector Applications.  

National Technical Information Service (NTIS)

The deposition of thin films of lead scandium tantalate (Pb(Sc1/2Ta1/2)O3) have been investigated by two processing routes. n he first, progress is reviewed for chemical vapour deposition in a purpose built low pressure reactor, utilising suitable modifie...

F. Ainger A. Patel N. M. Shorrocks C. Trundle R. W. Whatmore

1991-01-01

259

Integration of thin film decoupling capacitors.  

National Technical Information Service (NTIS)

Thin film decoupling capacitors consisting of submicron thick, sol-gel Pb(Zr,Ti)O(sub 3) layers between Pt electrodes on a Si substrate have recently been developed. Because the capacitor structure needs to be only (approximately)3 (mu)m thick, these devi...

T. Garino D. Dimos S. Lockwood

1994-01-01

260

Photothermal characterization of optical thin film coatings  

Microsoft Academic Search

Photothermal techniques are widely used in thin film characterizations and are particularly useful in studying laser-induced damage in optical coatings. The specific applications include measuring weak absorption, characterizing thermal conductivity, detecting local defects, and monitoring laser-interaction dynamics and determining laser damage thresholds as well as thermal impedance at boundaries of multilayers. We take an overview of the principle of photothermal

Z. L. Wu; M. Thomsen; P. K. Kuo; Y. Lu; C. Stolz; M. Kozlowski

1997-01-01

261

Thin Film Transistor-Addressed Display Device.  

National Technical Information Service (NTIS)

This is the final report on Contract DAAB07-72-C-0061; the objective of which was an examination of the feasibility of fabricating a multielement dot-matrix display using electroluminescent output and an integrated thin film transistor addressing array. T...

T. P. Brody F. C. Luo D. H. Davies

1977-01-01

262

Characterization of Field Exposed Thin Film Modules.  

National Technical Information Service (NTIS)

Test arrays of thin film modules have been deployed at the Solar Energy Centre near New Delhi, India since 2002-2003. Performances of these arrays were reported by O.S. Sastry. This paper reports on NREL efforts to support SEC by performing detailed chara...

A. Stokes J. H. Wohlgemuth M. Kumar O. S. Sastry Y. K. Singh

2012-01-01

263

Optical Thin Film Phase Quadrature Interferometry  

Microsoft Academic Search

An achromatic, fast time resolution, Michelson Doppler interferometric technique that is based on optical thin films and requires no scanning mechanisms has been developed. This was motivated by the pursuit to improve the time resolution of wide angle Michelson Doppler imaging interferometers for studies of the Earth's upper atmospheric winds and temperatures. The technique revolves around a mosaic of four

Susan H. C. P. McCall

1992-01-01

264

High Performance Thin Films for Microcircuits.  

National Technical Information Service (NTIS)

Thin-film hafnium-hafnium-dioxide capacitors have been fabricated on silicon substrates, and mounted and encapsulated in TO-5 cans. The temperature coefficient of capacitance can be as low as +50 ppm/C (up to 350 C) and seems to be smaller than that of th...

F. Huber W. H. Laznosky W. Witt

1967-01-01

265

Thin Films: Lean and mean superconductivity  

NASA Astrophysics Data System (ADS)

When it comes to superconducting device components, there is no such thing as too thin, but superconductivity has its limits. Now, ultrathin lead films with crystalline perfection have been shown to be able to carry large dissipationless currents down to a thickness of a few monolayers.

Yazdani, Ali

2006-03-01

266

The optical properties of YBCO thin films  

Microsoft Academic Search

We present strong evidence that there is no specific mid- infrared absorption band in YBCO and a generalised Drude model can be used to explain all of the observed features in the optical spectrum. A high vacuum, low temperature ATR experiment has been used to excite surface plasmons (SPP) on YBCO thin films at different temperatures. We have found that

Roger James Wallace

1997-01-01

267

Nonlinear Waves Guided by Thin Films.  

National Technical Information Service (NTIS)

The dispersion relations for wave guided by thin dielectric films surrounded on one or both sides by media with intensity-dependent refractive indices are solved numerically. A number of new modes as well new features in the usual low power modes are pred...

G. I. Stegeman C. T. Seaton J. Chilwell S. D. Smith

1984-01-01

268

Thin film thermocouples for internal combustion engines  

Microsoft Academic Search

The feasibility of fabricating thin film thermocouples on internal combustion engine hardware was investigated. The goal was to find a procedure that would be useful for the measurement of the surface metal temperature of valves, valve seats, combustion chamber surfaces, cylinder walls, and piston heads during engine operation. The approach pursued was to coat the engine hardware material with an

Kenneth G. Kreider

1986-01-01

269

Thin Film Solar Cells for Terrestrial Applications.  

National Technical Information Service (NTIS)

The goals of the project are to develop a terrestrial version of the CdS thin film solar cell that is demonstrably amenable to low cost mass production, and to establish data on the lifetime of such cells under the expected conditions of terrestrial use. ...

F. A. Shirland W. J. Biter E. W. Greeneigh T. P. Brody

1975-01-01

270

Residual stress measurement in YBCO thin films.  

SciTech Connect

Residual stress in YBCO films on Ag and Hastelloy C substrates was determined by using 3-D optical interferometry and laser scanning to measure the change in curvature radius before and after film deposition. The residual stress was obtained by appropriate analysis of curvature measurements. Consistent with residual thermal stress calculations based on the thermal expansion coefficient mismatch between the substrates and YBCO film, the measured residual stress in the YBCO film on Hastelloy C substrate was tensile, while it was compressive on the Ag substrate. The stress values measured by the two techniques were generally in good agreement, suggesting that optical interferometry and laser scanning have promise for measuring residual stresses in thin films.

Cheon, J. H.; Singh, J. P.

2002-05-13

271

Pulsed laser deposition of nasicon thin films  

NASA Astrophysics Data System (ADS)

We have deposited NASICON ( Na Super Ionic CONductor) films of thicknesses ranging from 100 to 600 nm, by Pulsed Laser Deposition (PLD), on SiO 2/Si substrates. The deposition rates varied from 6 × 10 -3 to 0.08 nm/pulse depending on the conditions employed. XPS measurements show that all elements are transferred from the target to the substrate and that the thin film composition is very close to that of the target. Film morphology depends upon the laser energy density at the target. Films deposited at about 2 J/cm 2 show a rough surface and a columnar structure. At lower energy density (400 mj/cm 2), a smoother surface is obtained. Electrical measurements show good ionic conductivity, and that the films are suitable for the fabrication of electrochemical gas sensors.

Izquierdo, R.; Hanus, F.; Lang, Th.; Ivanov, D.; Meunier, M.; Laude, L.; Currie, J. F.; Yelon, A.

1996-04-01

272

Kinetic impedance and depairing in thin and narrow superconducting films  

NASA Astrophysics Data System (ADS)

We use both Eilenberger-Usadel and Ginzburg-Landau (GL) theory to calculate the superfluid's temperature-dependent kinetic inductance for all currents up to the depairing current in thin and narrow superconducting films. The calculations apply to BCS weak-coupling superconductors with isotropic gaps and transport mean-free paths much less than the BCS coherence length. The kinetic inductance is calculated for the response to a small alternating current when the film is carrying a dc bias current. In the slow-experiment/fast-relaxation limit, in which the superconducting order parameter quasistatically follows the time-dependent current, the kinetic inductance diverges as the bias current approaches the depairing value. However, in the fast-experiment/slow-relaxiation limit, in which the the superconducting order parameter remains fixed at a value corresponding to the dc bias current, the kinetic inductance rises to a finite value at the depairing current. We then use time-dependent GL theory to calculate the kinetic impedance of the superfluid, which includes not only the kinetic reactance, but also the kinetic resistance of the superfluid arising from dissipation due to order-parameter relaxation. The kinetic resistance is largest for angular frequencies ? obeying ??s>1, where ?s is the order-parameter relaxation time, and for bias currents close to the depairing current. We also include the normal fluid's contribution to dissipation in deriving an expression for the total kinetic impedance. The Appendices contain many details about the temperature-dependent behavior of superconductors carrying current up to the depairing value.

Clem, John R.; Kogan, V. G.

2012-11-01

273

Polycrystalline thin-film solar cells and modules.  

National Technical Information Service (NTIS)

This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe(sub 2), CIS) and silicon films (Si-films) have made ...

H. S. Ullal J. L. Stone K. Zweibel T. Surek R. L. Mitchell

1991-01-01

274

Micro-Raman Analysis of Dielectric Thin Films.  

National Technical Information Service (NTIS)

The long-term motivation of our program Micro-Raman-Analysis of Dielectric Thin Films is the acquisition of an understanding of stress and the role of defects in the growth and optical performance of dielectric thin films. By dielectric films we mean film...

A. Schmid

1987-01-01

275

Substrate spacing and thin-film yield in chemical bath deposition of semiconductor thin films  

NASA Astrophysics Data System (ADS)

Thin-film yield in the chemical bath deposition technique is studied as a function of separation between substrates in batch production. Based on a mathematical model, it is proposed and experimentally verified in the case of CdS thin films that the film thickness reaches an asymptotic maximum with increase in substrate separation. It is shown that at a separation less than 1 mm between substrates the yield, i.e. percentage in moles of a soluble cadmium salt deposited as a thin film of CdS, can exceed 50%. This behaviour is explained on the basis of the existence of a critical layer of solution near the substrate, within which the relevant ionic species have a higher probability of interacting with the thin-film layer than of contributing to precipitate formation. The critical layer depends on the solution composition and the temperature of the bath as well as the duration of deposition. An effective value for the critical layer thickness has been defined as half the substrate separation at which 90% of the maximum film thickness for the particular bath composition, bath temperature and duration of deposition is obtained. In the case of CdS thin films studied as an example, the critical layer is found to extend from 0.5 to 2.5 mm from the substrate surface, depending on the deposition conditions.

Arias-Carbajal Reádigos, A.; García, V. M.; Gomezdaza, O.; Campos, J.; Nair, M. T. S.; Nair, P. K.

2000-11-01

276

Ferromagnetic resonance in Ni-Mn-Ga thin films and thin-film tubes  

Microsoft Academic Search

.  We report on FMR experiments performed for the first time on thin Ni-Mn-Ga films clamped to the mica substrates and then fully\\u000a released from them. The aim is to evaluate the role of magnetoelastic coupling in stressed Ni-Mn-Ga Heusler alloy films that\\u000a undergo martensitic transformation. The experimental results show that the difference in the effective magnetization 4?(Meff tubes-Meff films) is

J. Dubowik; I. Go?cia?ska; Y. Kudryavtsev

2008-01-01

277

Electronic transport properties of topological insulator films and low dimensional superconductors  

NASA Astrophysics Data System (ADS)

In this review, we present a summary of some recent experiments on topological insulators (TIs) and superconducting nanowires and films. Electron-electron interaction (EEI), weak anti-localization (WAL) and anisotropic magneto-resistance (AMR) effect found in topological insulator films by transport measurements are reported. Then, transport properties of superconducting films, bridges and nanowires and proximity effect in non-superconducting nanowires are described. Finally, the interplay between topological insulators and superconductors (SCs) is also discussed.

Xing, Ying; Sun, Yi; Singh, Meenakshi; Zhao, Yan-Fei; Chan, Moses H. W.; Wang, Jian

2013-10-01

278

Ferroelectric Thin Films for Electronic Applications  

NASA Astrophysics Data System (ADS)

This study yokes together the feasibility of a family of PbO-based perovskite-structured ferroelectric thin films as functional elements in nonvolatile random access memories (NVRAMs), in high capacity dynamic RAMs, and in a new class of flexure wave piezoelectric ultrasonic micromotors. The dielectric and ferroelectric properties of lead zirconate titanate (PZT) thin films were dependent on thickness; at saturation, the films were characterized by a relative permittivity of 1300, remanent polarization of 36 muC/cm^2 and breakdown strength of over 1 MV/cm. The temperature dependence of permittivity revealed an anomalous behavior with the film annealing temperature. Based on the ferroelectric properties in the bulk, thin films in the lead zirconate -lead zinc niobate (PZ-PZN) solid solution system at 8-12% PZN, examined as alternate compositions for ferroelectric memories, feature switched charges of 4-14 mu C/cm^2, with coercive and saturation voltages less than the semiconductor operating voltage of 5 V. Rapid thermally annealed lead magnesium niobate titanate films were privy to weak signal dielectric permittivity of 2900, remanent polarization of 11 muC/cm^2, and a storage density of 210 fC/mum^2 at 5 V; the films merit consideration for potential applications in ultra large scale integrated circuits as also ferroelectric nonvolatile RAMs. The high breakdown strength and relative permittivity of the PZT films entail maximum stored energy density 10^3 times larger than a silicon electrostatic motor. The longitudinal piezoelectric strain coefficient d_{33 } was measured to be 220 pC/N at a dc bias of 75 kV/cm. The transverse piezoelectric strain coefficient d_{31} bore a nonlinear relationship with the electric field; at 200 kV/cm, d _{31} was -88 pC/N. The development of the piezoelectric ultrasonic micromotors from the PZT thin films, and the architecture of the stator structures are described. Nonoptimized prototype micromotors show rotational velocities of 100-300 rpm at drives of 3-5 V.

Udayakumar, K. R.

279

Thin-film cadmium telluride solar cells  

NASA Astrophysics Data System (ADS)

This is the final technical progress report of a research program entitled Thin-Film Cadmium Telluride Solar Cells. The major objective was to demonstrate chemical vapor deposition (CVD)-grown CdTe devices with a photovoltaic efficiency of at least 10%. The work included: (1) CVD and characterization of p-CdTe films of controlled resistivity; (2) deposition and characterization of heterojunction partners; (3) surface passivation of CdTe; and (4) preparation and characterization of thin-film solar cells. The CVD of p-CdTe was optimized with emphasis on resistivity control through nonstoichiometry and extrinsic doping. Both carbon and oxygen were identified as acceptors. The use of thermal oxidation for surface passivation of CdTe was investigated using capacitance-voltage measurement. Device-quality thermal oxide can be prepared by hydrogen annealing of CdTe before oxidation. Deposition and characterization of CdS, CdO, and ZnO:In were also carried out. The best thin-film cell to date had a conversion efficiency near 9%.

1986-09-01

280

Adhesion assessment of copper thin films  

SciTech Connect

Nano-indentation testing has been used to quantitatively assess the adhesion of thin copper films, sputtered to thicknesses of 150 nm to 1500 nm. Copper films of low residual stress were deposited via RF diode cathode sputtering onto SiO{sub 2}/Si substrates. Overlayers of DC magnetron sputtered tungsten, 850 nm thick with high residual stress, were additionally used to provide a driving force for delamination. All films tested exhibited buckle-driven delamination, from which the interfacial toughness was estimated to be 0.2 - 2 J/m{sup 2}, which is comparable to the thermodynamic work of adhesion. The use of an overlayer requires extensions of existing models, but otherwise does not change the interfacial adhesion, allowing measurements of films that would not otherwise delaminate.

Kriese, M.D.; Gerberich, W.W. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering; Moody, N.R. [Sandia National Labs., Livermore, CA (United States)

1997-06-01

281

Thin uranium dioxide films with embedded xenon  

NASA Astrophysics Data System (ADS)

The ion beam assisted deposition (IBAD) method was applied as a means to incorporate Xe atoms into UO2 films to fabricate reference samples that are representative of an irradiated nuclear fuel without an actual reactor irradiation. The characterization of Xe content and the films microstructure was performed using Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDXS). A set of UO2 films with excellent control of Xe content ranging from ˜1.0 to 4.0 at.% was fabricated. The thin UO2 films deposited on single crystalline 4H-SiC substrates were found to be composed primarily of randomly oriented nanocrystalline grains and a small fraction of amorphous material. TEM analysis detected no Xe-filled bubbles at a scale of 2.5 nm or larger.

Usov, I. O.; Dickerson, R. M.; Dickerson, P. O.; Hawley, M. E.; Byler, D. D.; McClellan, K. J.

2013-06-01

282

Borides in thin film technology  

SciTech Connect

The borides of transition and rare-earth metals are considered for application as wear- and corrosion-resistant, decorative or thermionic coatings. After a review of physical vapor deposition (PVD) techniques used for the deposition of these coatings, a survey of investigations to apply these coatings is given. As a result of the strong directionality of covalent boron-boron bonds, boride coatings show an increasing tendency to amorphous film growth with increasing B/Me atomic ratio and, for rare-earth hexaborides, with decreasing metallic radius of the rare-earth metal. Mechanical and optical properties are strongly influenced by the crystallographic structure of the boride phase. Because of their high hardness combined with good adhesion, crystalline films based on the diborides of transition metals seem to be promising candidates for wear resistant coatings on cutting tools. Alloying of these films with nitrogen by reactive PVD processes results in the formation of extremely fine-grained multiphase hard coatings with excellent tribological and corrosion behavior, thus offering new applications in the coating of engineering components. Because of their distinct colorations, some of the hexaborides of rare-earth elements may be used as decorative coatings on consumer products like wristwatch casings or eyeglass frames. Another promising field is the development of thermionic coatings based on rare-earth hexaborides, which may offer the possibility of the production of inexpensive and simple high emission filaments.

Mitterer, C. [Institut fuer Metallkunde und Werkstoffpruefung, Leoben (Austria)

1997-10-01

283

Solid state thin-film lithium battery systems  

Microsoft Academic Search

Thin-film rechargeable lithium batteries, less than 15 ?m thick, are being developed as micro-power sources. Batteries with long cycle lives have been constructed with a variety of electrode materials and cell configurations onto thin ceramic, metal, and Si substrates. Improvements in the properties of several well-known cathode thin-film materials have been reported, while several novel thin-film anode materials have been

N. J. Dudney; B. J. Neudecker

1999-01-01

284

Extending the 3? method: Thermal conductivity characterization of thin films  

NASA Astrophysics Data System (ADS)

A lock-in technique for measurement of thermal conductivity and volumetric heat capacity of thin films is presented. The technique is based on the 3? approach using electrical generation and detection of oscillatory heat along a thin metal strip. Thin films are deposited onto the backside of commercial silicon nitride membranes, forming a bilayer geometry with distinct thermal parameters. Stepwise comparison to an adapted heat diffusion model delivers these parameters for both layers. Highest sensitivity is found for metallic thin films.

Bodenschatz, Nico; Liemert, André; Schnurr, Sebastian; Wiedwald, Ulf; Ziemann, Paul

2013-08-01

285

Switchable mirror based on Mg-Zr-H thin films  

Microsoft Academic Search

A Mg-Zr thin film is prepared on a glass substrate by co-sputtering of Mg and Zr targets and in situ sputtering of a thin Pd overlayer. The structural and optical properties of Mg-Zr and Mg-Zr-H thin film are investigated induced by hydrogen absorption and\\/or desorption at room temperature. Optical transmission and reflection data indicated that Mg-Zr-H thin film is the

Shanhu Bao; Yasusei Yamada; Kazuki Tajima; Ping. Jin; Masahisa Okada; Kazuki Yoshimura

286

Residual stresses in MEMS thin films  

NASA Astrophysics Data System (ADS)

Residual stresses in thin films are always a major concern in micromachining technology. The present work studies (1) behavior of residual stresses; (2) measurements of residual stresses; and (3) control and/or elimination of residual stresses. In-situ observations of buckling evolution of a polysilicon microbearn during etch of its underneath sacrificial layer were carried out. As etching went on, the buckling pattern evolved from mode I, the sinusoidal half-waves, to mode H, the constrained sinusoidal half-waves, to mode III, the conventional mode, and finally to mode IV, the blister-like local buckling. Closed formulae were derived from theoretical analysis. The formulae predict buckling patterns if the residual stress in a microbearn is known. On the other hand, the residual stress in a microbeam can be evaluated using the formulae from the buckling pattern. The theoretical results agree with the experimental observations. Micro-rotating-structures for local measurements of residual stresses in thin films were numerically simulated. A sensitivity factor was introduced and tabulated as a function of the structure parameters. Thereafter, a formula to calculate the residual stress is given and the residual stress can be easily evaluated from the rotating deflection. Residual stresses in both silicon nitride and polysilicon films were then determined using this technique and confirmed by the curvature method. As a result, micro-rotating-structures exhibited the ability to measure spatially and locally residual stresses in thin films with appropriate sensitivities. Residual stresses and materials characterization of polysilicon thin films prior to and following rapid thermal annealing were studied. In comparison with conventional heat treatment, high-temperature rapid thermal annealing can reduce residual stress in a few seconds. The experimental results also suggest that residual-stress evolution during annealing is induced by two main factors: (i) change in grain size and (ii) nitridation at the top surface of the thin film. High-temperature annealing induces recrystallization of the polycrystalline films and promotes grain growth. The fact that the grain growth is much more pronounced in samples after conventional heat treatment implies that the surface nitridation dominates the final stage of residual stress during rapid thermal annealing.

Zhang, Xin

287

Fabrication of single crystal PZT thin films on glass substrates  

Microsoft Academic Search

We have successfully transferred heteroepitaxial Pb(Zr,Ti)O3 (PZT) thin films from MgO substrates on to glass substrates. The transferred PZT thin films exhibit single crystal structure with ferroelectric properties similar to the as-grown epitaxial films. The transferring process comprises coating of Cr-metallized surface of epitaxial PZT thin films, pressing and cementing the Cr-metallized surface on to the glass substrates by silicone

Kenichiro Terada; Takaaki Suzuki; Isaku Kanno; Hidetoshi Kotera

2007-01-01

288

Elastic Properties of Molecular Glass Thin Films  

NASA Astrophysics Data System (ADS)

This dissertation provides a fundamental understanding of the impact of bulk polymer properties on the nanometer length scale modulus. The elastic modulus of amorphous organic thin films is examined using a surface wrinkling technique. Potential correlations between thin film behavior and intrinsic properties such as flexibility and chain length are explored. Thermal properties, glass transition temperature (Tg) and the coefficient of thermal expansion, are examined along with the moduli of these thin films. It is found that the nanometer length scale behavior of flexible polymers correlates to its bulk Tg and not the polymers intrinsic size. It is also found that decreases in the modulus of ultrathin flexible films is not correlated with the observed Tg decrease in films of the same thickness. Techniques to circumvent reductions from bulk modulus were also demonstrated. However, as chain flexibility is reduced the modulus becomes thickness independent down to 10 nm. Similarly for this series minor reductions in T g were obtained. To further understand the impact of the intrinsic size and processing conditions; this wrinkling instability was also utilized to determine the modulus of small organic electronic materials at various deposition conditions. Lastly, this wrinkling instability is exploited for development of poly furfuryl alcohol wrinkles. A two-step wrinkling process is developed via an acid catalyzed polymerization of a drop cast solution of furfuryl alcohol and photo acid generator. The ability to control the surface topology and tune the wrinkle wavelength with processing parameters such as substrate temperature and photo acid generator concentration is also demonstrated. Well-ordered linear, circular, and curvilinear patterns are also obtained by selective ultraviolet exposure and polymerization of the furfuryl alcohol film. As a carbon precursor a thorough understanding of this wrinkling instability can have applications in a wide variety of technologies.

Torres, Jessica

289

Nanoparticulate Alnico Thin Films with High Coercivity  

NASA Astrophysics Data System (ADS)

Alnico V (Fe--8% Al--14% Ni--24% Co--3% Cu) nanoparticulate thin films have been produced by dc magnetron sputtering. The films were sputtered on Si substrates for magnetic measurements and carbon-coated copper grids for TEM measurements. The as-deposited films have a fine grained microstructure with the bcc crystal structure. The as-made films were subjected to a full heat treatment which consists of heating the sample to 900 ^oC, then cooling it to 600 ^oC and finally annealing it at 600 ^oC for several hours. After the heat treatment, the thin films broke up into large nanoparticles (20-60 nm) surrounded by small nanoparticles (2 nm). Electron diffraction data showed that the annealed samples had an fcc structure. The maximum room temperature coercivity was found to be 2 kOe after 6h of annealing at 600 ^oC. The high coercivity could be due to strain that was induced during precipitation. The evolution of crystal structure and microstructure with annealing will be monitored and related to the observed magnetic properties.

Akdogan, Ozan; Hadjipanayis, George C.

2009-03-01

290

Atom trapping with a thin magnetic film  

NASA Astrophysics Data System (ADS)

We have demonstrated trapping of neutral atoms using magnetic fields produced by a thin magnetic film. The film was magnetized in alternating north/south stripes with a 10 ?m period. The magnetizable surface used was a hard disk platter provided by Hitachi Global Storage Technologies. Tube shaped traps were created with an additional radial bias field, and the traps were loaded with atoms from a ^87Rb BEC. Radial trap frequencies of up to 20 kHz were observed. Recent results may include imaging of the individual trap sites as well as experiments with the surface as an atomic mirror.

Boyd, Micah

2005-05-01

291

Reversible charge injection in antiferroelectric thin films  

NASA Astrophysics Data System (ADS)

High-energy storage antiferroelectric capacitors operated in a high speed require the quick release of stored charges after the removal of the electrical field accompanying ferroelectric-to-antiferroelectric phase transition. However, the phase-transition time can vary from a few nanoseconds to milliseconds due to the reversible charge injection into the film to temporally stabilize the high-field ferroelectric phase. The consequent theoretical modeling discloses the nearly Ohmic contact of an antiferroelectric Au/Cr/Pb(Zr0.95Ti0.05)O3/Pt thin-film capacitor for the charge injection unlike the Schottky emission of a typical ferroelectric capacitor.

Jiang, A. Q.; Tang, T. A.; Corkovic, S.; Zhang, Q.

2008-11-01

292

Photochemical Deposition of Patterned Gold Thin Films  

NASA Astrophysics Data System (ADS)

We present a novel route for patterned gold thin-film deposition on glass substrates with the help of UV-light irradiation. Chloroauric acid (HAuCl4) is used as a source material and sodium sulfite (Na2SO3) acts as a reducing agent in an aqueous solution. Ethylene diamine (EDA) is added to increase the solution stability. The deposition solution is injected on the substrate. A patterned metal mask is placed 5 mm above the substrate, and the solution is illuminated for 15 min by an ultrahigh-pressure mercury arc lamp. A patterned Au film with a thickness of 0.1-0.2 ?m is deposited.

Kumaran, Abbu Udaiyar Senthil; Miyawaki, Tetsuya; Ichimura, Masaya

2006-12-01

293

Nitrogen doped zinc oxide thin film  

SciTech Connect

To summarize, polycrystalline ZnO thin films were grown by reactive sputtering. Nitrogen was introduced into the films by reactive sputtering in an NO{sub 2} plasma or by N{sup +} implantation. All ZnO films grown show n-type conductivity. In unintentionally doped ZnO films, the n-type conductivities are attributed to Zn{sub i}, a native shallow donor. In NO{sub 2}-grown ZnO films, the n-type conductivity is attributed to (N{sub 2}){sub O}, a shallow double donor. In NO{sub 2}-grown ZnO films, 0.3 atomic % nitrogen was found to exist in the form of N{sub 2}O and N{sub 2}. Upon annealing, N{sub 2}O decomposes into N{sub 2} and O{sub 2}. In furnace-annealed samples N{sub 2} redistributes diffusively and forms gaseous N{sub 2} bubbles in the films. Unintentionally doped ZnO films were grown at different oxygen partial pressures. Zni was found to form even at oxygen-rich condition and led to n-type conductivity. N{sup +} implantation into unintentionally doped ZnO film deteriorates the crystallinity and optical properties and leads to higher electron concentration. The free electrons in the implanted films are attributed to the defects introduced by implantation and formation of (N{sub 2}){sub O} and Zni. Although today there is still no reliable means to produce good quality, stable p-type ZnO material, ZnO remains an attractive material with potential for high performance short wavelength optoelectronic devices. One may argue that gallium nitride was in a similar situation a decade ago. Although we did not obtain any p-type conductivity, we hope our research will provide a valuable reference to the literature.

Li, Sonny X.

2003-12-15

294

Transport behavior across the field-driven superconductor-insulator transition in amorphous indium oxide films  

NASA Astrophysics Data System (ADS)

Superconductor-insulator transition (SIT) in two-dimensional (2D) thin films is a beautiful realization of a zero temperature quantum phase transition (QPT) and has been explored both theoretically and experimentally over the last two decades. In addition to the several intrinsic ways (such as thickness) of tuning the transition, external magnetic field has been used to tune from one ground state to another in various condensed matter systems. Amorphous indium oxide thin films, with their unique capability of tuning the disorder level in the system easily, have been proven to be an excellent model system to study the transport mechanisms near and across the SIT in 2D. In this thesis, magnetic field-driven SIT in 2D films of amorphous InO x is studied. The goal of this work is to understand the microscopic transport mechanisms responsible for driving the SIT when the magnetic field direction is continually varied from being perpendicular to the sample plane to parallel. Applying a perpendicular magnetic field resulting in a clear field-driven SIT and a magneto-resistance peak on the insulating side in InO x films have been previously understood in a bosonic picture put forward by M. P. A. Fisher and coworkers. However, this boson-vortex duality picture is expected to give rise to markedly different transport characteristics when the magnetic field is applied parallel to the sample plane. Features found in the parallel-field transport data however can also be explained by the bosonic picture, thereby questioning the applicability of the hitherto successful models to the physics of SIT. An isotropic magnetic field value, where the sample has the exact same resistance irrespective of the angle between the sample plane and magnetic field direction, is found. This isotropic point lies at field values above the critical field (Bc) of the SIT (in both perpendicular and parallel configurations) and above the magnetoresistance peak. The isotropic point is very weakly dependent on disorder levels and is temperature-independent. These observations suggest a possible fermionic role in the conduction near the quantum critical point of the SIT and would require newer models to be developed to completely understand the physics. Current-voltage characteristics measured in superconducting samples (below Bc) show that the true superconducting behavior (with a critical current to conduction) appears only in the B = 0 limit. Especially, application of a small magnetic field (˜ 0.2 T) drives the system into a flux flow regime and hence dissipative. The role of this dissipative channel in the superconducting phase in driving the SIT is not well understood. Competing roles of dissipation and bosonic mechanisms need to be treated simultaneously to decipher the underlying physics. When magnetic field is applied to a mesoscopic scale superconducting film, the film breaks into puddles of superconductors and insulators, thereby suggesting percolation-type transport behavior near the quantum critical point. Interestingly, the nonuniform nature of conduction occurs only in magnetic fields below and above Bc at very low temperature below ˜ 400 mK and the sample is completely homogeneous at B c. A complete understanding of the scale of inhomogeneous regions and their role in driving the QPT are still unclear. And the results presented suggest that more experimental and theoretical efforts are needed for understanding the physics near the QPT clearly.

Kim, Min-Soo

295

Growth of superconducting Sr2RuO4 thin films  

NASA Astrophysics Data System (ADS)

Sr2RuO4 is a superconductor with a low transition temperature (Tc~1 K), but has a unique character of p-wave symmetry of the order parameter, demanding epitaxial thin films for Josephson junction studies. We have grown c-axis oriented epitaxial films by a pulsed laser deposition technique on (001) surfaces of (LaAlO3)0.3(SrAl0.5Ta0.5O3)0.7 substrates. Careful tuning of growth conditions yielded in a layer-by-layer growth of high crystallinity films. The films show a residual resistivity ratio (?300 K/?2 K) as large as 82 and a superconducting transition with a zero resistivity at 0.6 K.

Krockenberger, Y.; Uchida, M.; Takahashi, K. S.; Nakamura, M.; Kawasaki, M.; Tokura, Y.

2010-08-01

296

Photofluxonic detection - A new mechanism for infrared detection in superconducting thin films  

NASA Astrophysics Data System (ADS)

A new model is proposed in which a photon of energy E = hf is absorbed by a superconducting film to create a pair of equal and opposite fluxons (or vortices), each with quantized flux Phi(0) = h/2e. An applied current sweeps these fluxons to opposite edges of the film, causing a voltage pulse with time-integrated magnitude Phi(0), and leading to a time-averaged voltage responsivity Rv = Phi(0)/E = 1/(2ef). This is directly analogous to photoconductive detection in a semiconductor via creation of electron-hole pairs. Data on an ultrathin granular NbN film are presented which indicate a responsivity of 6000 V/W in red light, in agreement with the model. This is promising for the development of a sensitive high-speed infrared detector using thin films of either low or high Tc superconductors.

Kadin, A. M.; Leung, M.; Smith, A. D.; Murduck, J. M.

1990-12-01

297

Optimizing absorptance in nanostructured thin films  

NASA Astrophysics Data System (ADS)

To construct a solar cell with maximal efficiency it is necessary to minimise the remittances of the cell across the solar spectrum. Thin-film solar cells allow for production of solar cells with reduced cost, weight and rare mineral consumption; furthermore, engineering at the nanoscale may achieve the high levels of solar absorption attainable with traditional, thicker cells. Columnar thin films (CTFs) have the potential to fulfil these requirements, as by infiltrating the voids between the column with a fluid and by tailoring the shape of the columns, the optical properties can be tuned. Here we present a mathematical framework for calculating the absorptance of such an infiltrated CTF. Also presented are some preliminary numerical results, based on a titanium oxide CTF. These simulations imply that by decreasing the columnar angle (the angle between the column and the substrate) much higher levels of absorption can be achieved, as compared to a CTF with columns oriented normal to the substrate.

Anderson, Tom H.; Mackay, Tom G.

2013-09-01

298

Polycrystalline thin films FY 1992 project report  

SciTech Connect

This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting next-generation'' options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called government/industry partnerships'') that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.

Zweibel, K. (ed.)

1993-01-01

299

Polycrystalline thin films FY 1992 project report  

SciTech Connect

This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting ``next-generation`` options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called ``government/industry partnerships``) that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.

Zweibel, K. [ed.

1993-01-01

300

Thin film photovoltaic panel and method  

DOEpatents

A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

Ackerman, Bruce (El Paso, TX); Albright, Scot P. (El Paso, TX); Jordan, John F. (El Paso, TX)

1991-06-11

301

DNA Strand Patterns on Aluminium Thin Films  

PubMed Central

A new patterning method using Deoxyribose Nucleic Acid (DNA) strands capable of producing nanogaps of less than 100 nm is proposed and investigated in this work. DNA strands from Bosenbergia rotunda were used as the fundamental element in patterning DNA on thin films of aluminium (Al) metal without the need for any lithographic techniques. The DNA strands were applied in buffer solutions onto thin films of Al on silicon (Si) and the chemical interactions between the DNA strands and Al creates nanometer scale arbitrary patterning by direct transfer of the DNA strands onto the substrate. This simple and cost-effective method can be utilized in the fabrication of various components in electronic chips for microelectronics and Nano Electronic Mechanical System (NEMS) applications in general.

Khatir, Nadia Mahmoudi; Banihashemian, Seyedeh Maryam; Periasamy, Vengadesh; Majid, Wan Haliza Abd; Rahman, Saadah Abdul; Shahhosseini, Fatemeh

2011-01-01

302

PST thin films for electrocaloric coolers  

NASA Astrophysics Data System (ADS)

Relaxor behaviour in a thin film of partially ordered PbSc0.5Ta0.5O3 (PST) was confirmed via slim P-E loops and the frequency dependence of the temperature at which the dielectric constant is maximum. Indirect measurements of the electrocaloric effect suggest that removing a field of 774 kV cm-1 yields a temperature change of -3.5 °C to -6.9 °C over a broad range of operating temperatures near room temperature (1-127 °C), with a correspondingly large refrigerant capacity of 662 J kg-1. In addition to low electrical hysteresis, there is negligible thermal hysteresis. PST thin films are therefore promising for EC cooling near room temperature.

Correia, T. M.; Kar-Narayan, S.; Young, J. S.; Scott, J. F.; Mathur, N. D.; Whatmore, R. W.; Zhang, Q.

2011-04-01

303

EBSD analysis of electroplated magnetite thin films  

NASA Astrophysics Data System (ADS)

By means of electron backscatter diffraction (EBSD), we analyse the crystallographic orientation of electroplated magnetite thin films on Si/copper substrates. Varying the voltage during the electroplating procedure, the resulting surface properties are differing considerably. While a high voltage produces larger but individual grains on the surface, the surfaces become smoother on decreasing voltage. Good quality Kikuchi patterns could be obtained from all samples; even on individual grains, where the surface and the edges could be measured. The spatial resolution of the EBSD measurement could be increased to about 10 nm; thus enabling a detailed analysis of single magnetite grains. The thin film samples are polycrystalline and do not exhibit a preferred orientation. EBSD reveals that the grain size changes depending on the processing conditions, while the detected misorientation angles stay similar.

Koblischka-Veneva, A.; Koblischka, M. R.; Teng, C. L.; Ryan, M. P.; Hartmann, U.; Mücklich, F.

2010-05-01

304

Superconducting epitaxial thin films of CeNi{sub x}Bi{sub 2} with a bismuth square net structure  

SciTech Connect

We have grown highly epitaxial and phase pure thin films of the arsenic-free pnictide compound CeNi{sub x}Bi{sub 2} on (100) MgO substrates by reactive molecular beam epitaxy (RMBE). X-ray diffraction and reflection high-energy electron diffraction of the films confirm the ZrCuSiAs structure with a Bi square net layer. Superconductivity was observed in magnetization and resistivity measurements for x= 0.75 to 0.93 in these CeNi{sub x}Bi{sub 2} thin films with the highest critical temperature of 4.05 K and a resistive transition width of 0.1 K for x= 0.86. Our results indicate that thin film deposition by RMBE provides a tool to synthesize high-quality pnictide superconductors of the novel 112 type.

Buckow, Alexander; Kupka, Katharina; Retzlaff, Reiner; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2012-10-15

305

Fabrication of ZnO thin film transistors by atomic force microscopy nanolithogrophy through zinc thin films  

Microsoft Academic Search

Zinc oxide (ZnO) thin film transistors were fabricated by local anodic oxidation (LAO) of polycrystalline zinc film using an atomic force microscope (AFM). Nanometer-thin zinc film can be locally transformed into p -type zinc oxide by an anodic oxidation technique using an AFM at room temperature. With this fabrication process, we have fabricated a backgate, Schottky-barrier-contact type thin film ZnO

Jeff T. H. Tsai; Ben H. B. Lee; Ming S. Yang

2009-01-01

306

Fabrication of ZnO thin film transistors by atomic force microscopy nanolithogrophy through zinc thin films  

Microsoft Academic Search

Zinc oxide (ZnO) thin film transistors were fabricated by local anodic oxidation (LAO) of polycrystalline zinc film using an atomic force microscope (AFM). Nanometer-thin zinc film can be locally transformed into p-type zinc oxide by an anodic oxidation technique using an AFM at room temperature. With this fabrication process, we have fabricated a backgate, Schottky-barrier-contact type thin film ZnO transistor.

J. T. H. Tsai; Ben H. B. Lee; Ming S. Yang

2009-01-01

307

Properties of n-type ZnN thin films as channel for transparent thin film transistors  

Microsoft Academic Search

In this work we fabricated, by rf magnetron sputtering from a ZnN target, zinc nitride thin films and examined their properties in order to be used as channel layer in thin film transistors. The films were deposited at 100 W rf power and the Ar pressure was 5 mTorr. The zinc nitride thin films were n-type, and depending on the thickness they

E. Aperathitis; V. Kambilafka; M. Modreanu

2009-01-01

308

Organic thin-film transistors of phthalocyanines  

Microsoft Academic Search

Organic thin-film field-effect transistors (OTFTs) are emerging as attractive candi- dates for low-price, large-area, and flexible circuit applications. A variety of organic com- pounds have been utilized as active semiconductor materials for OTFTs, among which phthalocyanine compounds have attracted considerable attention owing to their remarkable chemical and thermal stability as well as good field-effect performance. Here, we review re- cent

Liqiang Li; Qingxin Tang; Hongxiang Li; Wenping Hu; Xiaodi Yang; Zhigang Shuai; Yunqi Liu; Daoben Zhu

2008-01-01

309

Structures for dense, crack free thin films  

DOEpatents

The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); De Jonghe, Lutgard C. (Lafayette, CA)

2011-03-08

310

Dynamics effects in thin ferromagnetic films  

Microsoft Academic Search

Dynamics effects in the ferromagnetic thin films below and above the reorientation transition is studied. Particular attention is given to the effects of the dipole-dipole interaction on the spin-wave dynamics above the transition and the dynamics and decay of the topological excitations below the transition. The dipole-dipole interaction, although irrelevant for the 3D magnet, plays a major role for the

Artem G. Abanov

1998-01-01

311

Picosecond laser ablation of thin copper films  

Microsoft Academic Search

The ablation process of thin copper films on fused silica by picosecond laser pulses is investigated. The ablation area is characterized using optical and scanning electron microscopy. The single-shot ablation threshold fluence for 40 ps laser pulses at 1053rnm has been determinated to Fthres=172rmJ\\/cm2. The ablation rate per pulse is measured as a function of intensity in the range of

J. Jandeleit; G. Urbasch; H. D. Hoffmann; H.-G. Treusch; E. W. Kreutz

1996-01-01

312

Cathodoluminescence of thin films of cadmium fluoride  

Microsoft Academic Search

The cathodoluminescence (CL) spectrum of thin films of cadmium fluoride (CdF2), activated by MnC12 (2 wt. %) at T = 90 K, consists of bands with ~rnax = 415 and 530 nm[ 1-3 ]. It is found that a change in the accelerating anode voltage (UA) from 8 to 2 kV causes a reduction in the halfwidth of the band

V. A. Bernatskii

1993-01-01

313

Oxide thin film heterostructure IR detector  

Microsoft Academic Search

Pyroelectric Mn and Sb doped-Pb(Zr,Ti)O3(PMSZT)\\/YBa2Cu3O 7-y (YBCO) thin film heterostructure has been integrated with Si using a YSZ buffer layer. Their pyroelectric properties and IR responsivity have been studied. Doping of the PZT with Mn and Sb was used to tune the ferroelectric transition temperatures to lower values, and hence to modify the pyroelectric and dielectric properties of the pyroelectric

Y. Q. Xu; A. Ignatiev; N. J. Wu

1998-01-01

314

Annihilation mechanisms in thin film grain growth  

Microsoft Academic Search

Grain growth in succinonitrile thin films is dominated by topological effects [Scripta Metall. Mater. 30 (1994) 633; Metall. Mater. Trans. A 26 (1995) 1061; Philos. Mag. 79(4) (1999) 763]. The topological transformations are effected by the shortened length of the grain boundaries [R.T. De Hoff, in: H. Weiland, B.L. Adams, A.D. Rollet, Grain Growth in Polycrystalline Materials III, TMS, 1998,

M. A Palmer; M. E Glicksman; K Rajan

2003-01-01

315

Laser annealing of thin organic films  

NASA Astrophysics Data System (ADS)

Microstructure of defects in organic solar cells containing PEDOT:PSS:Sorbitol layer has been studied and conditions for successful pulsed laser annealing of them have been determined. Investigation with oblique illumination showed that radial symmetry of fine structure is an intrinsic property of either separated discotic defects or block structure. Our study shows that pulsed laser annealing of organic thin films in inert atmosphere has promising future.

Agashkov, A. V.; Ivlev, G. D.; Filippov, V. V.; Kashko, I. A.; Shulitski, B. G.

2010-09-01

316

Low voltage electrowetting using thin fluoroploymer films  

Microsoft Academic Search

This paper investigates the nonideal electrowetting behavior of thin fluoroploymer films. Results are presented for a three phase system consisting of: (1) an aqueous water droplet containing sodium dodecyl sulfate (SDS), (2) phosphorous-doped silicon topped with SiO2 and an amorphous fluoroploymer (aFP) insulating top layer on which the droplet is situated, and (3) a dodecane oil that surrounds the droplet.

Shaun Berry; Jakub Kedzierski; Behrouz Abedian

2006-01-01

317

Packaging material for thin film lithium batteries  

DOEpatents

A thin film battery including components which are capable of reacting upon exposure to air and water vapor incorporates a packaging system which provides a barrier against the penetration of air and water vapor. The packaging system includes a protective sheath overlying and coating the battery components and can be comprised of an overlayer including metal, ceramic, a ceramic-metal combination, a parylene-metal combination, a parylene-ceramic combination or a parylene-metal-ceramic combination.

Bates, John B. (116 Baltimore Dr., Oak Ridge, TN 37830); Dudney, Nancy J. (11634 S. Monticello Rd., Knoxville, TN 37922); Weatherspoon, Kim A. (223 Wadsworth Pl., Oak Ridge, TN 37830)

1996-01-01

318

PST thin films for electrocaloric coolers  

Microsoft Academic Search

Relaxor behaviour in a thin film of partially ordered PbSc0.5Ta0.5O3 (PST) was confirmed via slim P-E loops and the frequency dependence of the temperature at which the dielectric constant is maximum. Indirect measurements of the electrocaloric effect suggest that removing a field of 774 kV cm-1 yields a temperature change of -3.5 °C to -6.9 °C over a broad range

T. M. Correia; S. Kar-Narayan; J. S. Young; J. F. Scott; N. D. Mathur; R. W. Whatmore; Q. Zhang

2011-01-01

319

Materials availability for thin film solar cells  

Microsoft Academic Search

Materials availability is one of the most important factors when we consider the mass-production of next generation photovoltaic devices. ``In (indium)'' is a vital element to produce high efficient thin film solar cells such as InP and CuIn(Ga)Se2 but its lifetime as a natural resource is suggested to be of order of 10~15 years. The lifetime of a specific natural

Yunosuke Makita

1997-01-01

320

Deposition of Thin Films by Sputtering  

Microsoft Academic Search

\\u000a Thin films deposition techniques are generally classified in two main groups: Chemical Vapour Deposition (CVD) and Physical\\u000a Vapour Deposition (PVD). The last one encompasses sputtering and evaporation. They are applied, dependent on particular requirements\\u000a of the production technology. Obviously, they have their specific advantages and simultaneously introduce given limitations.\\u000a Below, selected PVD techniques will be classified and described in details.

W. Gulbi?ski

321

Temperature distribution on thin-film metallizations  

Microsoft Academic Search

The time-dependent temperature distribution of a thin-film stripe has been solved rigorously using two successive Laplace transforms on both time and coordinate. For a good conducting stripe with a delta-shaped crack it is shown that the temperature distribution can be very adequately described by the steady-state solution provided only that the time scale involved is of the order of 10-3

Yi-Shung Chaug; Huei Li Huang

1976-01-01

322

Optical parameters of pyrite thin films  

Microsoft Academic Search

Optical properties of pyrite thin films obtained by iron sulfuration have been studied in samples of different iron thickness (0.12–0.5 ?m) sulfurated at different temperatures in the range 620–770 K. Dispersion values of the optical absorption coefficient and refractive index for wavelengths 0.8–3.0 ?m have been determined by fitting the optical transmission spectra in this range using a multivariable nonlinear

C. de Las Heras; G. Lifante

1997-01-01

323

Enhanced gilbert damping in thin ferromagnetic films.  

PubMed

The precession of the magnetization of a ferromagnet is shown to transfer spins into adjacent normal metal layers. This "pumping" of spins slows down the precession corresponding to an enhanced Gilbert damping constant in the Landau-Lifshitz equation. The damping is expressed in terms of the scattering matrix of the ferromagnetic layer, which is accessible to model and first-principles calculations. Our estimates for permalloy thin films explain the trends observed in recent experiments. PMID:11909427

Tserkovnyak, Yaroslav; Brataas, Arne; Bauer, Gerrit E W

2002-02-28

324

Electrocaloric devices based on thin-film heat switches  

NASA Astrophysics Data System (ADS)

We describe a new approach to refrigeration, heat pumping, and electrical generation that allows one to exploit the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators and heat pumps or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches based on thin layers of liquid crystals, the efficiency of electrocaloric thin-film devices can be at least as high as that of current thermoelectric devices. Advanced heat switches that may use carbon nanotubes would enable thin-film refrigerators and generators to outperform conventional vapor-compression devices.

Epstein, Richard I.; Malloy, Kevin J.

2009-09-01

325

Stress in Switchable Mirror Thin Film Resulting from Gasochromic Switching  

NASA Astrophysics Data System (ADS)

To enable the practical use of the switchable mirror thin film, an improvement of switching durability is crucial. One of the causes of film degradation is the modification of the Pd cap layer in accordance with the volume change upon hydrogenation and dehydrogenation, which is expected to be related to inner stress in switchable mirror thin films. In this study, we observed stress change in the switchable mirror thin film resulting from gasochromic switching and investigated the relationship between stress and switching durability. We found that the inner stress of the Pd layer is directly related to the switching durability of switchable mirror thin films.

Kazuki Yoshimura,; Kazuki Tajima,; Yasusei Yamada,; Masahisa Okada,

2010-07-01

326

Stable multilayer thin films composed of gold nanoparticles and lysozyme  

NASA Astrophysics Data System (ADS)

It needs appropriately attractive forces to construct multilayer thin films by layer-by-layer (LBL) assembly technique. It is feasible to prepare multilayer thin films on glass slides with negatively charged gold nanoparticles and positively charged lysozyme through the electrostatic LBL assembly technique. The gold nanoparticles/lysozyme multilayer thin films are highly stable; immersion in 0.1 M HCl, NaOH, and surfactant sodium dodecyl sulfate aqueous solutions cannot destroy the films. The highly stable gold nanoparticles/lysozyme multilayer thin films have potential application in long-term antibacterial coating.

Su, Yan-lei; Li, Chao

2008-01-01

327

In situ growth and characterization of ultrahard thin films.  

PubMed

Results concerning the operation of a new ultrahigh vacuum (UHV) ion-beam assisted deposition system for in situ investigation of ultrahard thin films are reported. A molecular beam epitaxy (MBE) chamber attached to a surface science system (SPEAR) has been redesigned for deposition of cubic-boron nitride thin films. In situ thin film processing capability of the overall system is demonstrated in preliminary studies on deposition of boron nitride films on clean Si (001) substrates, combining thin film growth with electron microscopy and surface characterization, all in situ. PMID:9779834

Bengu, E; Collazo-Davila, C; Grozea, D; Landree, E; Widlow, I; Guruz, M; Marks, L D

1998-08-15

328

Transport measurements on a thin Nb film with square array of nanoscale magnetic dots.  

NASA Astrophysics Data System (ADS)

Transport measurements (R vs. T, R vs. B, and V-I characteristics) were made on a thin Nb film deposited on top of a square array of nanoscale magnetic dots [1]. These measurements established that in many ways this system behaved like a Josephson junction array (JJA). We hypothesized that the stray magnetic field of the dots reduced the superconductivity in the Nb film in such a way as to make the film a superconductor-weaker superconductor-superconductor (S-S-S) JJA. Studies of the VIs in the presence of a radio frequency (rf) signal revealed the appearance of Shapiro steps in the VI's. The voltage location at which the steps occurred follow the Josephson relation Vn=n*N*(h/2)*?, where n=1,2,3, etc, N is the number of junctions along the current direction, and ? is the frequency of the rf signal. Sample provided by Dr. Axel Hoffmann from Argonne National Laboratory and Dr. Ivan K. Schuller from UCSD. [1] J. I. Martin, Y. Jaccard, A. Hoffmann, J. Nogues, J. M. George, J. I. Vicent, and I. K. Schuller, J. Appl. Physics. 84, 411 (1998)

Gómez, Luis B.; Mast, David B.

2002-03-01

329

Asymmetric grain distribution in phthalocyanine thin films  

SciTech Connect

Many electronic and optical properties of organic thin films depend on the precise morphology of grains. Iron phthalocyanine thin films are grown on sapphire substrates at different temperatures to study the effect of grain growth kinematics and to experimentally quantify the grain size distribution in organic thin films. The grain size is measured with an atomic force microscope and the data is processed and analyzed with well-known image segmentation algorithms. For relevant statistics, over 3000 grains are evaluated for each sample. The data show pronounced asymmetric grain growth with increasing deposition temperature from almost spherical grains at room temperature to elongated needlelike shapes at 260 deg. C. The average size along the major axis increases from 35 to 200 nm and along the minor axis from 25 to 90 nm. The distribution is almost symmetric at low-deposition temperatures, but becomes lognormal at higher temperatures. Strikingly, the major axis and minor axis of the elliptically shaped grains have different distributions at all temperatures due to the planar asymmetry of the molecule.

Gentry, K. Paul; Gredig, Thomas; Schuller, Ivan K. [Department of Physics and Astronomy, California State University-Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840 (United States); Department of Physics and Astronomy, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)

2009-11-01

330

Epitaxial Growth of Metal and Superconductor Oxide Films  

SciTech Connect

In this presentation we will discuss the epitaxial growth of metal and superconductor oxide layers on bi-axial textured substrates. It is well established now that to obtain superior critical current densities for YBCO superconductors we need biaxially textured crystalline substrates. One way to accomplish biaxial texturing in a superconducting material is to grow epitaxial YBCO onto biaxial textured substrates. Superconducting oxide layers cannot be deposited directly on textured metal substrates for example Ni and Ni-W, and Cu since superconductors interact adversely with the substrate in a manner that degrades the superconductor material, especially during the high temperatures at which the superconductor materials are deposited or processed. It is also desirable to have a textured Ni layer on paramagnetic Ni-W substrate since Ni-W is more oxidative in nature. To overcome these adverse interactions, a buffer layer of material is often deposited between the substrate and the superconducting material to form a chemical barrier between the metal substrate and the superconductor. At present we are developing biaxial textured seed metal buffer layer materials inexpensively by electrodeposition method. We successfully electroplated biaxially textured Au on Ni, Ni-W and Cu and also Ni on Ni-W and Cu. In this meeting we will discuss the epitaxial growth of electrodeposited Ni and Au and also the superconducting YBCO material prepared epitaxially by PLD method.

Bhattacharya, Raghu [National Renewable Energy Laboratory (NREL); Spagnol, Priscila [National Renewable Energy Laboratory (NREL); Christen, David K [ORNL; Lee, Dominic F [ORNL

2005-01-01

331

GRAIN GROWTH AND RESIDUAL STRESS IN BST THIN FILMS  

Microsoft Academic Search

Residual stress plays an important role in the determination of properties and lifetime of thin film dielectric films. While residual stress can be caused by a variety of factors, grain growth is of particular importance. Using theoretical approaches the stress due to grain growth and coalescence are predicted for magnesium doped barium strontium titanate thin films on magnesium oxide single

W. D. NOTHWANG; M. W. COLE; S. G. HIRSCH

2005-01-01

332

Pattern formation during delamination and buckling of thin films  

Microsoft Academic Search

Using a simple lattice model, we study the failure of compressively strained thin films on solid substrates. Our simulations reproduce much of the observed phenomenology of thin film blistering. In particular, we observe a peculiar form of stress relief in which a wrinkle of delaminated film propagates along a sinusoidal path. At higher intrinsic strains, the sinusoidal wrinkles bifurcate, forming

Kevin M. Crosby; R. Mark Bradley

1999-01-01

333

Rapid optical measurement of surface roughness of polycrystalline thin films  

Microsoft Academic Search

Excimer laser crystallization is the most commonly employed technology for fabricating low temperature polycrystalline silicon (LTPS) thin films. Investigations on the surface roughness of polycrystalline silicon (poly-Si) thin films become an important issue because the surface roughness of poly-Si film is widely believed to be related to its electrical characteristics. A simple optical measurement system for rapid surface roughness measurement

Chil-Chyuan Kuo; Chin-Sheng Chao

2010-01-01

334

Thickness-dependent properties of sprayed iridium oxide thin films  

Microsoft Academic Search

Iridium oxide thin films with variable thickness were deposited by spray pyrolysis technique (SPT), onto the amorphous glass substrates kept at 350°C. The volume of iridium chloride solution was varied to obtain iridium oxide thin films with thickness ranging from 700 to 2250Å. The effect of film thickness on structural and electrical properties was studied. The X-ray diffraction (XRD) studies

P. S Patil; P. S Chigare; S. B Sadale; T Seth; D. P Amalnerkar; R. K Kawar

2003-01-01

335

Fission fragment response characteristics of thin film plastic scintillators  

Microsoft Academic Search

Results are presented of measurements of the energy loss response of thin film plastic scintillators using fission fragments for a range of film thicknesses from 0.8 to 6 mum. Previously reported anomalous response behaviour of the thin film plastic scintillators of 4-5 mum thickness was not observed. The improved understanding of the light response characteristics of TFPS makes possible their

C. B. Franklyn

1988-01-01

336

Unsteady thin-film flow over a heated stretching sheet  

Microsoft Academic Search

The unsteady flow in a thin viscous liquid film over a heated horizontal stretching surface are analyzed considering the stretching velocity and the temperature distribution in their general forms. An evolution equation for the film thickness, that retains the convective heat transport effects, is derived using long-wave theory of thin liquid film and is solved numerically for some representative values

Bidyut Santra; Bhabani S. Dandapat

2009-01-01

337

Bulge testing of single and dual layer thin films  

Microsoft Academic Search

The bulge testing technique determines the mechanical properties of solid thin films by measuring the deformation that forms in response to the application of a controlled differential pressure to a thin film window. By comparing the pressure- displacement relation with a mechanical model, the elastic modulus and residual stress in the film can be measured. While the bulge testing technique

Dryver R. Huston; Patricia S. Bunta; Brian Esserab

338

Power absorption by thin films on microwave windows  

Microsoft Academic Search

A recent theory for power absorption by continuous thin surface films on microwave windows is compared with experimental data, focusing on diamond gyrotron windows. Two measurement techniques, the dc method by Jory and the radio-frequency (RF) method by Heidinger et al., are used to estimate the fraction of the average power absorbed by the thin films, assuming that these films

Herman L. Bosman; Yue Ying Lau; Ronald M. Gilgenbach

2004-01-01

339

Enhanced SPR sensing based on micro-patterned thin films  

Microsoft Academic Search

Micro-patterned thin films interrogated in the Kretschmann configuration of SPR could extend the detection range to lower concentrations and small biomolecules due to a greater sensitivity. This was achieved with the same instrumentation and analysis methodologies developed for SPR with continuous films. The plasmonic properties of micro-patterned thin films composed of various layers of Ag and Au were investigated to

Ludovic S. Live; Julien Breault-Turcot; Kim-Ly Nguyen; Jean-Francois Masson

2011-01-01

340

Buckle driven delamination in thin hard film compliant substrate systems  

Microsoft Academic Search

Deformation and fracture of thin films on compliant substrates are key factors constraining the performance of emerging flexible substrate devices. These systems often contain layers of thin polymer, ceramic and metallic films and stretchable interconnects where differing properties induce high normal and shear stresses. As long as the films remain bonded to the substrates, they may deform far beyond their

Megan J. Cordill; David Price Adams; Neville Reid Moody; Edmundo Corona; Marian S. Kennedy; David F. Bahr; Reedy Earl David Jr

2010-01-01

341

Buckle Driven Delamination in Thin Hard Film Compliant Substrate Systems  

Microsoft Academic Search

Deformation and fracture of thin films on compliant substrates are key factors constraining the performance of emerging flexible substrate devices. [1-3] These systems often contain layers of thin polymer, ceramic and metallic films and stretchable interconnects where differing properties induce high normal and shear stresses. [4] As long as the films remain bonded to the substrates, they may deform far

N. R. Moody; E. D. Reedy; E. Corona; D. P. Adams; M. S. Kennedy; M. J. Cordill; D. F. Bahr

2010-01-01

342

Thin film cadmium telluride photovoltaic cells  

SciTech Connect

This report describes research to develop to vacuum-based growth techniques for CdTe thin-film solar cells: (1) laser-driven physical vapor deposition (LDPVD) and (2) radio-frequency (rf) sputtering. The LDPVD process was successfully used to deposit thin films of CdS, CdTe, and CdCl{sub 2}, as well as related alloys and doped semiconductor materials. The laser-driven deposition process readily permits the use of several target materials in the same vacuum chamber and, thus, complete solar cell structures were fabricated on SnO{sub 2}-coated glass using LDPVD. The rf sputtering process for film growth became operational, and progress was made in implementing it. Time was also devoted to enhancing or implementing a variety of film characterization systems and device testing facilities. A new system for transient spectroscopy on the ablation plume provided important new information on the physical mechanisms of LDPVD. The measurements show that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a fraction that is highly excited internally ({ge} 6 eV), and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater. 19 refs.

Compaan, A.; Bohn, R. (Toledo Univ., OH (United States))

1992-04-01

343

Metal-doped magnetite thin films.  

PubMed

This paper investigates magnetite (Fe3O4) thin film containing a small amount of a metal element. The films are prepared by rf sputtering with a composite target of ceramic iron oxide with metal chips. Low-temperature magnetization of magnetite containing 5.3%Ge reveals that the film contains some magnetically weak coupling grains. The metal element Mg reduces both hematite (alpha-Fe2O3) and magnetite, resulting in single-phase wüstite (Fe1-xO). In contrast, adding Ge selectively reduces hematite, while magnetite remains unreactive. According to the free energy of reaction, the element Ge is able to reduce hematite only, whereas the element Mg is capable of reducing both hematite and magnetite. This property is in good agreement with the experiment results. PMID:22905582

Abe, Seishi; Ping, De Hai; Nakamura, Shintaro; Ohnuma, Masato; Ohnuma, Shigehiro

2012-06-01

344

Two-fluid measurements on thin films  

NASA Astrophysics Data System (ADS)

The two-fluid technique to measure the dielectric constant and thickness of a thin polymeric film is discussed. The advantages include the ability to make a non-contacting measurement both of the effective electrical thickness of the film as well as the dielectric constant. The requirements for an accurate measurement are examined and the error as a function of the cell spacing, sample thickness, and dielectric constant of the second fluid are evaluated. The specifications of both the cell and the second fluid are examined. For the cell, it must be stable to good accuracy with handling, settable to small gaps, and have a well-defined electrode area through the use of a guard ring with a narrow guard gap. A design of a holder that is suitable for films from 6 micrometers to 50 micrometers is illustrated.

Mopsik, Frederick I.

1992-05-01

345

Electrohydrodynamic instabilities in thin trilayer liquid films.  

SciTech Connect

When DC or AC electric fields are applied to a thin liquid film, the interface may become unstable and form a series of pillars. We examine how the presence of a second liquid interface influences pillar dynamics and morphologies. For perfect dielectric films, linear stability analysis of a lubrication-approximation-based model shows that the root mean square voltage governs the pillar behavior. For leaky dielectric films, Floquet theory is applied to carry out the linear stability analysis, and reveals that the accumulation of free charge at each interface depends on the conductivities in the adjoining phases and that high frequencies of the AC electric field may be used to control this accumulation at each interface independently. The results presented here may of interest for the controlled creation of surface topographical features in applications such as patterned coatings and microelectronics.

Roberts, Scott A.; Kumar, Satish (University of Minnesota %3CU%2B2013%3E Twin Cities)

2010-11-01

346

Magnetoimpedance spectroscopy of epitaxial multiferroic thin films  

NASA Astrophysics Data System (ADS)

The detection of true magnetocapacitance (MC) as a manifestation of magnetoelectric coupling (MEC) in multiferroic materials is a nontrivial task, because pure magnetoresistance (MR) of an extrinsic Maxwell-Wagner-type dielectric relaxation can lead to changes in capacitance [G. Catalan, Appl. Phys. Lett.APPLAB0003-695110.1063/1.2177543 88, 102902 (2006)]. In order to clarify such difficulties involved with dielectric spectroscopy on multiferroic materials, we have simulated the dielectric permittivity ?' of two dielectric relaxations in terms of a series of one intrinsic film-type and one extrinsic Maxwell-Wagner-type relaxation. Such a series of two relaxations was represented in the frequency- (f-) and temperature- (T-) dependent notations ?' vs f and ?' vs T by a circuit model consisting in a series of two ideal resistor-capacitor (RC) elements. Such simulations enabled rationalizing experimental f-, T-, and magnetic field- (H-) dependent dielectric spectroscopy data from multiferroic epitaxial thin films of BiMnO3 (BMO) and BiFeO3 (BFO) grown on Nb-doped SrTiO3. Concomitantly, the deconvolution of intrinsic film and extrinsic Maxwell-Wagner relaxations in BMO and BFO films was achieved by fitting f-dependent dielectric data to an adequate equivalent circuit model. Analysis of the H-dependent data in the form of determining the H-dependent values of the equivalent circuit resistors and capacitors then yielded the deconvoluted MC and MR values for the separated intrinsic dielectric relaxations in BMO and BFO thin films. Substantial intrinsic MR effects up to 65% in BMO films below the magnetic transition (TC?100 K) and perceptible intrinsic MEC up to -1.5% near TC were identified unambiguously.

Schmidt, Rainer; Ventura, Jofre; Langenberg, Eric; Nemes, Norbert M.; Munuera, Carmen; Varela, Manuel; Garcia-Hernandez, Mar; Leon, Carlos; Santamaria, Jacobo

2012-07-01

347

Thin Film Evolution Over a Thin Porous Layer: Modeling a Tear Film on a Contact Lens  

NASA Astrophysics Data System (ADS)

We examine a mathematical model that describes the behavior of the pre-contact lens tear film of a human eye. Our work examines the effect of contact lens thickness and lens permeability and slip on the film dynamics. A mathematical model for the evolution of the tear film is derived using a lubrication approximation applied to the hydrodynamic equations of motion in the fluid film and the porous layer. The model is a nonlinear fourth order partial differential equation subject to boundary conditions and an initial condition for post-blink film evolution. We find that increasing the lens thickness, permeability and slip all contribute to an increase in the film thinning rate although for parameter values typical for contact lens wear these modifications are minor. The presence of the contact lens can, however, fundamentally change the nature of the rupture dynamics as the inclusion of the porous lens leads to rupture in finite time rather than infinite time.

Anderson, Daniel; Nong, Kumnit

2010-11-01

348

A sequential thin-film deposition equipment for in-situ fabricating all-solid-state thin film lithium batteries  

Microsoft Academic Search

To improve the interfacial quality and electrochemical performance of all-solid-state thin film lithium batteries (TFLBs), a sequential thin film deposition equipment has been developed. This equipment consists of a dry glove box for packing TFLB and four vacuum chambers, one chamber of them for deposition lithium film anode by flash thermal evaporation, and the other three vacuum chambers for deposition

Wen-Yuan Liu; Zheng-Wen Fu; Qi-Zong Qin

2007-01-01

349

Processing of magnetostrictive thin film devices  

NASA Astrophysics Data System (ADS)

(Tb,Dy)Fesb2 intermetallic alloys exhibit very large magnetostrictive strains. Alloys with composition near Tbsb{0.3}Dysb{0.7}Fesb2, known as Terfenol-D, are of particular interest because this is the composition where room temperature anisotropy compensation occurs and the moment can be easily rotated. Terfenol-D has a cubic Laves phase structure and exhibits maximum magnetostrictive strain along $ directions at room temperature. Bulk Terfenol-D tends to grow as twinned dendritic sheets with $ orientation. Recently, there has been increased interest in Terfenol-D thin film devices. Crystallographic texture can change the magnetostrictive properties of thin films. It is the purpose of this research to study the effect of postdeposition annealing and magnetic annealing treatments on the microstructure of Terfenol-D thin films. It is predicted that textured films can be obtained by exploiting increased magnetocrystalline anisotropy at elevated temperatures. This would improve the low field magnetostrictive strains attainable for device applications. Also of recent interest is the fabrication of magnetostrictive composites. Increased toughness and durability are attainable at the cost of reduced magnetostrictive performance. Terfenol-D composites have been made with polymers. Composites with metals would be stronger and tougher but conventional high temperature processing routes cause unwanted reactions. Temperatures high enough to allow appreciable diffusion for sintering would also allow the metal binder phase to interdiffuse with Terfenol-D. This work also examines the feasibility of explosive compaction of Terfenol-D-metal composites. The short duration, on the order of microseconds, of the pressure and temperature pulse experienced by the powder leads to compaction at near room temperature. This is expected to prevent unwanted reactions between Terfenol-D and the metal binder.

Loveless, Michael Ray

350

Overview of current bulk and thick film high temperature superconductor processing strategies  

SciTech Connect

A review of processing strategies to prepare conductor-configured high temperature superconductors is presented along with a tabulation of recent results obtained using a variety of processing procedures to produce wires, tapes, monoliths, and thick films of high temperature superconducting material. 32 refs., 1 tab.

Ott, K.C.; Quinn, R.K.

1990-01-01

351

Ferroelectric Thin Films: Deposition, Advanced Film Characterization and Novel Device Concepts  

Microsoft Academic Search

In this work, current problems of ferroelectric thin film deposition are reviewed: Film stoichiometry, mechanical film stress, and self-polarization. Advanced film characterization includes the profiling of film properties over film thickness: the refractive index by Multi Angle Spectroscopic Ellipsometry, the pyroelectric coefficient profile by Laser Intensity Modulation Method, and polarization and space charge profiling by Atomic Force Microscopy. Novel device

G. Suchaneck; G. Gerlach

2006-01-01

352

Precision measurement of the ab-plane London penetration depth in high temperature superconducting thin films  

NASA Astrophysics Data System (ADS)

The temperature change of the in-plane penetration depth ?? ab ( T)=? ab ( T)-? ab (0) of HTS thin films was determined with an experimental resolution of better than 0.2Å using a novel dc-technique based on the measurement of the magnetic field dependence of the critical current of bicrystal grain boundary Josephson junctions (GBJs). Over a wide temperature range the data obtained for different high temperature superconductors confirm with high accuracy the theoretical prediction for a d x 2 -y 2-symmetry of the superconducting order parameter in the limit of weak coupling.

Froehlich, O. M.; Beck, A.; Richter, P.; Gross, R.

1996-02-01

353

Search for new materials: phase spread alloy thin film fabrication and characterization  

NASA Astrophysics Data System (ADS)

We use the phase spread alloy (PSA) method of fabricating compositionally heterogeneous thin films as an efficient way to produce and screen new, interesting materials (e.g. superconductors, magnetoresistive compounds, etc.). This method uses co-sputtering to deposit material with smoothly varying element concentration across a substrate. Both local and non-local probes are used to verify the composition of the sample. Using the La-Si-C system as an example, we perform x-ray fluorescence from a synchrotron source, x-ray diffraction from a lab source, atomic force microscopy, and infrared spectroscopy on one sample to verify the presence of different phases and their properties.

Marsh, Moses; Basaran, Ali; de La Venta, Jose; Khatib, Omar; Shpyrko, Oleg; Basov, Dmitri; Schuller, Ivan

2012-02-01

354

Features of technology of high-temperature superconductor films for microwave filters  

NASA Astrophysics Data System (ADS)

The characteristics of fourth-order bandpass microwave filters based on high-temperature super-conductor (HTS) films have been numerically simulated and experimentally measured for the devices based on YBCO films purchased from Theva GmbH (Munich) and manufactured at the Institute for Physics of Microstructures (Nizhni Novgorod). Experimental data were used to determine the parameters of the surface impedance model for the HTS films. The results show that HTS-based filters with high performance characteristics can be obtained using HTS films manufactured by different technologies.

Vendik, I. B.; Vendik, O. G.; Zemlyakov, K. N.; Kolmakova, I. V.; Sitnikova, M. F.; Tural'chuk, P. A.; Masterov, D. V.; Pavlov, S. A.; Parafin, A. E.

2011-05-01

355

The CdTe Thin Film Solar Cell - AN Overview  

Microsoft Academic Search

The basic physical aspects of the CdTe-thin film solar cell in its various embodiments are reviewed. Deposition techniques are briefly described, results of present pilot-line production efforts and the future potential are discussed, which make the CdTe thin film solar cell a promising candidate for low cost and well-above 10% module-efficiency. A detailed costing model for thin film solar cells

Dieter Bonnet

1992-01-01

356

Overview and Challenges of Thin Film Solar Electric Technologies  

SciTech Connect

In this paper, we report on the significant progress made worldwide by thin-film solar cells, namely, amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium diselenide (CIGS). Thin-film photovoltaic (PV) technology status is also discussed in detail. In addition, R&D and technology challenges in all three areas are elucidated. The worldwide estimated projection for thin-film PV technology production capacity announcements are estimated at more than 5000 MW by 2010.

Ullal, H. S.

2008-12-01

357

Multilayer thin-film coatings for optical communication systems  

Microsoft Academic Search

Recent developments in thin-film coatings for optical communication systems are reviewed. Particular emphasis is given to thin-film designs with dispersion related to the photonic crystal superprism effect. A single dispersive coating may be used for multiplexing or demultiplexing several wavelength channels by spatial beam shifting. ?2004 Optical Society of America OCIS codes: (310.0310) Thin films, (060.2340) Fiber optics components; (260.2030)

Martina Gerken; David A. B. Miller

2004-01-01

358

Novel organic thin films for ultrahigh density information storage  

Microsoft Academic Search

A novel organic compound, N-Cyano, N?-Phenyl, Urea (CPU) was synthesized. Its monomer and polymer thin films were prepared by different deposition methods on highly ordered pyrolytic graphite substrate (HOPG). The CPU thin films were characterized by Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). Ultrahigh density information storage with the thin films using scanning tunneling microscope (STM) has

Yanlin Song; Liping Ma; Sishen Xie; Shijin Pang; Lei Jiang; Daoben Zhu

2000-01-01

359

Microstructure and Surface Morphology of YSZ Thin Films  

Microsoft Academic Search

In present study yttrium stabilized zirconia (YSZ) thin films were deposited on Alloy-600 (Ni72\\/Cr16\\/Fe8) and optical quartz substrates using e-beam deposition technique controlling deposition parameters: substrate temperature and electron gun power influencing thin film deposition mechanism. The dependences of thin film structure and surface morphology on these parameters were investigated by X-ray diffraction, scanning electron microscopy (SEM), and atomic force

Giedrius LAUKAITIS; Julius DUDONIS

360

New Switchable Mirror Based on Magnesium-Niobium Thin Film  

Microsoft Academic Search

We found that palladium-capped magnesium-niobium alloy thin films show a good optical switching property when they are exposed to a hydrogen-containing atmosphere. A switchable mirror based on a magnesium-niobium thin film was prepared on a glass substrate by cosputtering of Mg and Nb targets. Mg1-xNbx thin films with a 4 nm Pd overlayer can be switched reversibly between shiny mirror

Shanhu Bao; Yasusei Yamada; Kazuki Tajima; Masahisa Okada; Kazuki Yoshimura

2007-01-01

361

Electrophoretic Deposition of Thin Films of Nanoparticles  

NASA Astrophysics Data System (ADS)

Nanoparticles have attracted considerable interest recently due to their size-dependent, quantum confinement characteristics, which make them attractive for an array of optical, magnetic, and electronic devices. For nanoparticles to be employed in an array of commercial and industrial applications, a technique for the facile, site-selective assembly of homogeneous, densely packed, defect-free thin films must be realized. Widely used methods for casting nanoparticle (NP) constituents into films have recognized limitations, including the inability to achieve both large-scale ordering of the nanoparticles and robust chemical and structural properties. NP deposition schemes also require an understanding of both the NP dynamics in suspension and the interactions that govern nanoparticle-substrate and nanoparticle-nanoparticle binding. Although research has been conducted on the assembly of nanoparticles with a distribution of surface charge states, little has been done on the assembly of like-charged nanoparticles. The only NP deposition scheme that considers the physical characteristics of the NPs in the film formation and incorporates the most favorable attributes of NP deposition is electrophoretic deposition (EPD). Recent progress in the NP EPD will be the emphasis of this presentation. Highlighted are the recent discoveries of the size dependence of the thickness of iron oxide NP films and the fabrication of free-standing NP films.

Dickerson, James

2008-10-01

362

Laser conditioning of optical thin films  

NASA Astrophysics Data System (ADS)

Results are presented that show the damage thresholds of e-beam deposited multi-layer HfO2/SiO2 thin films can be permanently increased by a factor of 2 to 3 by illumination with subthreshold fluences of laser light. This subthreshold illumination procedure is referred to as laser conditioning. The films used in this study were prepared by three different physical-vapor-deposition techniques: ion-beam sputtering, plasma plating, and e-beam evaporation. Only the e-beam deposited films showed consistent and significant improvement with laser conditioning. Of the material pairs examined (HfO2/SiO2, ZrO2/SiO2, and TiO2/SiO2), HfO2/SiO2 gave the greatest and most consistent damage improvement with conditioning. The number of layers and the reflective or transmissive characteristics of the HfO2/SiO2 films were found to have little impact on laser conditioning of the film. The results show that the damage thresholds of a wide range of e-beam deposited coatings (e.g., HR's, polarizers, etc.) can be improved by laser conditioning. Several possible conditioning mechanisms are examined.

Wolfe, C. R.; Kozlowski, M. R.; Campbell, J. H.; Rainer, F.; Morgan, A. J.; Gonzales, R. P.

1989-05-01

363

Instabilities during the formation of electroactive polymer thin films.  

PubMed

The solvent-induced film structure of poly(n-vinyl carbazole) (PVK) thin films on indium tin oxide (ITO)-coated glass was examined. PVK thin films were prepared via spin-coating using five different solvents. We investigated the relationship between the solvent characteristics and film properties, including surface roughness and structure, film thickness, and density. The spin-coated polymer thin films are not in thermodynamic equilibrium; rather, the film properties are affected by the dynamics of the spin-coating process. We found that water present in tetrahydrofuran (THF) induces dewetting of PVK films during the spin-coating process. Solvents with a high evaporation rate lead to high surface roughness due to Marangoni convection. The results show that the surface roughness and structure of the films are dominated by the dynamics of the film formation process, rather than thermodynamic interactions between the polymer and solvents. PMID:15779962

Luo, Shyh-Chyang; Craciun, Valentin; Douglas, Elliot P

2005-03-29

364

Elastic Properties of Amorphous Thin Films  

NASA Astrophysics Data System (ADS)

In an attempt to gain a better understanding of the universal low temperature properties of amorphous solids, a technique has been developed for measuring the elastic properties of amorphous thin films. The technique has been applied to a study of electron beam evaporated amorphous SiO_2 films with thicknesses ranging from 0.75 nm to 1000 nm. We find that the anomalous elastic properties associated with tunneling states in bulk amorphous solids are still present in films with thicknesses as small as 0.75 nm. This indicates that the universal thermal and elastic properties found in amorphous solids are not due to interactions which occur between tunneling states, at least on length scales on the order of the minimum film thickness studied. Additionally, the technique has also been applied to a study of thin films of amorphous silicon and germanium produced by a variety of techniques. In this work, for the first time, we have found two amorphous solids whose low temperature lattice vibrations can be varied by over an order of magnitude depending on the method of preparation. In particular, we report on the elastic properties of a-Si prepared by electron beam evaporation and chemical vapor deposition. We find that the elastic properties of a-Si, which are similar to those found in all amorphous solids, can be significantly altered by the addition of hydrogen which passivates the dangling bonds of the a-Si structure. The presence of hydrogen reduces the density of tunneling states by approximately one order of magnitude below the lower limit observed in all other amorphous solids. The implications of these findings on our understanding of the lattice vibrations of amorphous solids will be discussed.

White, Bruce Edward, Jr.

365

CuSbS 2 thin film formed through annealing chemically deposited Sb 2S 3–CuS thin films  

Microsoft Academic Search

We report a method to produce CuSbS2 thin films through a solid state reaction at 400°C involving thin films of Sb2S3 (0.5?m) and CuS. The precursor thin films were produced by chemical bath deposition on glass substrates. Thin films of Sb2S3 were deposited at 10°C using thiosulfatoantimonate(III) complex. Subsequently, thin films of CuS were deposited onto these films from a

Y. Rodr??guez-Lazcano; M. T. S. Nair; P. K. Nair

2001-01-01

366

Thin films of metal-organic frameworks.  

PubMed

The fabrication of thin film coatings of metal-organic frameworks (MOFs) on various substrates is discussed in this critical review. Interestingly, the relatively few studies on MOF films that have appeared in the literature are limited to the following cases: [Zn4O(bdc)3] (MOF-5; bdc=1,4-benzenedicarboxylate), [Cu3(btc)2] (HKUST-1; btc=1,3,5-benzenetricarboxylate), [Zn2(bdc)2(dabco)] (dabco=1,4-diazabicyclo[2.2.2]octane), [Mn(HCOO)], [Cu2(pzdc)2(pyz)] (CPL-1; pzdc=pyrazine-2,3-dicarboxylate, pyz=pyrazine), [Fe(OH)(bdc)] (MIL-53(Fe)) and [Fe3O(bdc)3(Ac)] (MIL-88B; Ac=CH3COO-). Various substrates and support materials have been used, including silica, porous alumina, graphite and organic surfaces, i.e. self-assembled monolayers (SAMs) on gold, as well as silica surfaces. Most of the MOF films were grown by immersion of the selected substrates into specifically pre-treated solvothermal mother liquors of the particular MOF material. This results in more or less densely packed films of intergrown primary crystallites of sizes ranging up to several microm, leading to corresponding film thicknesses. Alternatively, almost atomically flat and very homogenous films, with thicknesses of up to ca. 100 nm, were grown in a novel stepwise layer-by-layer method. The individual growth steps are separated by removing unreacted components via rinsing the substrate with the solvent. The layer-by-layer method offers the possibility to study the kinetics of film formation in more detail using surface plasmon resonance. In some cases, particularly on SAM-modified substrates, a highly oriented growth was observed, and in the case of the MIL-53/MIL-88B system, a phase selective deposition of MIL-88B, rather than MIL-53(Fe), was reported. The growth of MOF thin films is important for smart membranes, catalytic coatings, chemical sensors and related nanodevices (63 references). PMID:19384445

Zacher, Denise; Shekhah, Osama; Wöll, Christof; Fischer, Roland A

2009-03-09

367

Physical Properties of Thin Film Semiconducting Materials  

NASA Astrophysics Data System (ADS)

The physics and chemistry of semiconducting materials is a continuous question of debate. We can find a large stock of well-known properties but at the same time, many things are not understood. In recent years, porous silicon (PS-Si), diselenide of copper and indium (CuInSe2 or CIS) and metal oxide semiconductors like tin oxide (SnO2) and zinc oxide (ZnO) have been subjected to extensive studies because of the rising interest their potential applications in fields such as electronic components, solar panels, catalysis, gas sensors, in biocompatible materials, in Li-based batteries, in new generation of MOSFETS. Bulk structure and surface and interface properties play important roles in all of these applications. A deeper understanding of these fundamental properties would impact largely on technological application performances. In our laboratory, thin films of undoped and antimony-doped films of tin oxide have been deposited by chemical vapor deposition. Spray pyrolysis was used for ZnO. CIS was prepared by flash evaporation or close-space vapor transport. Some of the deposition parameters have been varied, such as substrate temperature, time of deposition (or anodization), and molar concentration of bath preparation. For some samples, thermal annealing was carried out under oxygen (or air), under nitrogen gas and under vacuum. Deposition and post-deposition parameters are known to strongly influence film structure and electrical resistivity. We investigated the influence of film thickness and thermal annealing on structural optical and electrical properties of the films. Examination of SnO2 by x-ray diffraction showed that the main films are polycrystalline with rutile structure. The x-ray spectra of ZnO indicated a hexagonal wurtzite structure. Characterizations of CIS films with compositional analysis, x-ray diffraction, scanning microscopy, spectrophotometry, and photoluminescence were carried out.

Bouras, N.; Djebbouri, M.; Outemzabet, R.; Sali, S.; Zerrouki, H.; Zouaoui, A.; Kesri, N.

2005-10-01

368

Strain tuning of ferroelectric thin films.  

SciTech Connect

Predictions and measurements of the effect of biaxial strain on the properties of epitaxial ferroelectric thin films and superlattices are reviewed. Results for single-layer ferroelectric films of biaxially strained SrTiO{sub 3}, BaTiO{sub 3}, and PbTiO{sub 3} as well as PbTiO{sub 3}/SrTiO{sub 3} and BaTiO{sub 3}/SrTiO{sub 3} superlattices are described. Theoretical approaches, including first principles, thermodynamic analysis, and phase-field models, are applied to these biaxially strained materials, the assumptions and limitations of each technique are explained, and the predictions are compared. Measurements of the effect of biaxial strain on the paraelectric-to-ferroelectric transition temperature (T{sub c}) are shown, demonstrating the ability of percent-level strains to shift T{sub c} by hundreds of degrees in agreement with the predictions that predated such experiments. Along the way, important experimental techniques for characterizing the properties of strained ferroelectric thin films and superlattices, as well as appropriate substrates on which to grow them, are mentioned.

Schlom, D. G.; Chen, L.-Q.; Eom, C.-B.; Rabe, K. M.; Streiffer, S. K.; Triscone, J.-M.; Penn State Univ.; Univ. of Wisconsin at Madison; Rutgers Univ.; Univ. of Geneva

2007-01-01

369

Fluorination of amorphous thin-film materials with xenon fluoride  

DOEpatents

A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

Weil, R.B.

1987-05-01

370

Measuring the elastic modulus of soft thin films on substrates  

Treesearch

... materials such as soft polymers, cellulosic sheets, and biological materials. ... for the analysis of metal and dielectric films on semiconductor substrates and thus ... A semi-analytical model that treats the thin film and substrate as two springs ...

371

Fluorination of amorphous thin-film materials with xenon fluoride  

DOEpatents

A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

Weil, Raoul B. (Haifa, IL)

1988-01-01

372

Multivariate classification of BPSG thin films using Mahalanobis distances.  

National Technical Information Service (NTIS)

Infrared absorption spectra of borophosphosilicate glass (BPSG) thin films were collected to develop a rapid classification method for determining if the films are within the desired specifications. Classification of samples into good and bad categories w...

S. Zhang J. E. Franke T. M. Niemczyk D. M. Haaland J. N. Cox

1995-01-01

373

Heteroepitaxial ferroelectric ZnSnO3 thin film.  

PubMed

We investigated the ferroelectric characteristics of an epitaxial perovskite ZnSnO(3) thin film on a (111) SrRuO(3)/(111) SrTiO(3) substrate fabricated by pulsed laser deposition. We confirmed that the ZnSnO(3) thin film was epitaxially grown on the substrate, forming large terraces on the surface of the ZnSnO(3) thin film. The ZnSnO(3) thin film exhibited a high ferroelectric polarization of approximately 47 microC/cm(2), which was further supported by first-principles calculations. PMID:19476356

Son, Jong Yeog; Lee, Geunhee; Jo, Moon-Ho; Kim, Hyungjun; Jang, Hyun M; Shin, Young-Han

2009-06-24

374

Dye-Sensitization Of Nanocrystalline ZnO Thin Films  

SciTech Connect

Nannocrystalline and nanoporus thin films of ZnO were synthesized on glass substrates by using wet chemical drop casting method. X-ray diffraction measurements on these samples confirmed the formation of ZnO nanocrystallites in hexagonal wurtzite phase with mean size of {approx}20 nm. Photo sensitization of these nanostructured ZnO thin films was carried out using three types of dyes Rhodamine 6 G, Chlorophyll and cocktail of Rhodamine 6 G and Chlorophyll in 1:1 ratio. Dye sensitized ZnO thin films showed enhanced optical absorption in visible spectral region compared to the pristine ZnO thin films.

Ajimsha, R. S.; Tyagi, M.; Das, A. K.; Misra, P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2010-12-01

375

Electrochromic properties of nanocrystalline MoO 3 thin films  

Microsoft Academic Search

Electrochromic MoO3 thin films were prepared by a sol–gel spin-coating technique. The spin-coated films were initially amorphous; they were calcined, producing nanocrystalline MoO3 thin films. The effects of annealing temperatures ranging from 100 °C to 500 °C were investigated. The electrochemical and electrochromic properties of the films were measured by cyclic voltammetry and by in-situ optical transmittance techniques in 1 M LiClO4\\/propylene carbonate

Chao-Sheng Hsu; Chih-Chieh Chan; Hung-Tai Huang; Chia-Hsiang Peng; Wen-Chia Hsu

2008-01-01

376

Growth and characterisation of electrodeposited ZnO thin films  

Microsoft Academic Search

The electrochemical method has been used to deposit zinc oxide (ZnO) thin films from aqueous zinc nitrate solution at 80 °C onto fluorine doped tin oxide (FTO) coated glass substrates. ZnO thin films were grown between ? 0.900 and ? 1.025 V vs Ag\\/AgCl as established by voltammogram. Characterisation of ZnO films was carried out for both as-deposited and annealed films in order to

J. S. Wellings; N. B. Chaure; S. N. Heavens; I. M. Dharmadasa

2008-01-01

377

Density of thin vapour-deposited films of zinc selenide  

Microsoft Academic Search

The density of thin vapour-deposited films of zinc selenide was determined by spectrophotometry combined with Rutherford backscattering spectrometry. Bulk stoichiometry of the films was measured by Rutherford backscattering spectroscopy. It was found that the films were relatively rich in Se. Depth profile study of the films, by x-ray photoelectron spectroscopy, revealed that surfaces were rich in Se while, away from

E. E. Khawaja; S. M. A. Durrani; A. B. Hallak; M. A. Salim; M. S. Hussain

1994-01-01

378

Electrical properties of ultra thin evaporated polypropylene films  

Microsoft Academic Search

A ultrathin polypropylene film (PP film) is deposited on a glass substrate from an evaporating source in vacuum. The temperature of the glass substrate is kept at 100°C during the deposition. The thin PP film is about 100Å in thickness. The film shows a self-healing breakdown in the high field region, and the electrode area gradually decreases. The electric strength

S. Ochiai; A. Maeda; T. Ogawa; T. Takagi; M. Ieda; T. Mizutani

1993-01-01

379

Development of thin film solar cell based on Cu 2ZnSnS 4 thin films  

Microsoft Academic Search

Cu2ZnSnS4 (hereafter CZTS) thin films were successfully formed by vapor-phase sulfurization of precursors on a soda lime glass substrate (hereafter SLG) and a Mo-coated one (hereafter Mo-SLG). From the optical properties, we estimate the band-gap energy of this thin film as 1.45–1.6eV which is quite close to the optimum value for a solar cell. By using this thin film as

Hironori Katagiri; Kotoe Saitoh; Tsukasa Washio; Hiroyuki Shinohara; Tomomi Kurumadani; Shinsuke Miyajima

2001-01-01

380

Solid phase crystallization of amorphous silicon on glass by thin film heater for thin film transistor (TFT) application  

Microsoft Academic Search

A new process for solid phase crystallization (SPC) of amorphous silicon (a-Si) using thin film heater is reported. With this localized Ti silicide thin film heater, we successfully crystallized 500 Å-thick a-Si in a few minutes without any thermal deformation of glass substrate. The size of crystallized silicon grain was abnormally big (30–40 ?m). Polycrystalline thin film transistors (TFT) fabricated

Byoung Dong Kim; Hunjoon Jung; Gi-bum Kim; Seung-ki Joo

2003-01-01

381

Optimizing the growth of vanadyl-phthalocyanine thin films for high-mobility organic thin-film transistors  

Microsoft Academic Search

To achieve high-mobility organic thin-film transistors (OTFTs), growth of vacuum-evaporated vanadyl-phthalocyanine (VOPc) thin films as the active layer was studied and optimized by varying the process conditions of the substrate temperature, deposition rate, and dielectric type. On the popularly used SiO2 gate dielectric, the surface morphology of the VOPc thin film exhibited closely packed terraced grains when the substrate temperature

X. J. Yu; J. B. Xu; W. Y. Cheung; N. Ke

2007-01-01

382

The influence of La substitution and oxygen reduction in ambipolar La-doped YBa2Cu3Oy thin films  

NASA Astrophysics Data System (ADS)

We report hole and electron doping in Y0.38La0.62(Ba2-xLax)Cu3Oy thin films synthesized by the pulsed laser deposition technique and subsequently annealed in oxygen ambient or in a vacuum. X-ray diffraction studies suggested a single phase in p-type thin films and transport measurements showed a superconductor-to-insulator transition at x = 0.46. Hall measurements indicated electrons were successfully doped when the thin films were annealed in vacuum. The n-type samples demonstrated metallic behaviour within moderate temperature ranges, and a low in-plane resistivity (?ab) and a high carrier density for 0.32 ? x ? 0.46. The increase in ?ab for higher La doping levels, probably caused by charge compensation, is also discussed. The present result could be a significant step in searching for electron-doped superconductivity in the YBa2Cu3Oy system.

Zeng, S. W.; Huang, Z.; Wang, X.; Lü, W. M.; Liu, Z. Q.; Zhang, B. M.; Dhar, S.; Venkatesan, T.; Ariando

2012-12-01

383

Rechargeable thin-film electrochemical generator  

DOEpatents

An improved electrochemical generator is disclosed. The electrochemical generator includes a thin-film electrochemical cell which is maintained in a state of compression through use of an internal or an external pressure apparatus. A thermal conductor, which is connected to at least one of the positive or negative contacts of the cell, conducts current into and out of the cell and also conducts thermal energy between the cell and thermally conductive, electrically resistive material disposed on a vessel wall adjacent the conductor. The thermally conductive, electrically resistive material may include an anodized coating or a thin sheet of a plastic, mineral-based material or conductive polymer material. The thermal conductor is fabricated to include a resilient portion which expands and contracts to maintain mechanical contact between the cell and the thermally conductive material in the presence of relative movement between the cell and the wall structure. The electrochemical generator may be disposed in a hermetically sealed housing.

Rouillard, Roger (Beloeil, CA); Domroese, Michael K. (South St. Paul, MN); Hoffman, Joseph A. (Minneapolis, MN); Lindeman, David D. (Hudson, WI); Noel, Joseph-Robert-Gaetan (St-Hubert, CA); Radewald, Vern E. (Austin, TX); Ranger, Michel (Lachine, CA); Sudano, Anthony (Laval, CA); Trice, Jennifer L. (Eagan, MN); Turgeon, Thomas A. (Fridley, MN)

2000-09-15

384

Tin oxide transparent thin-film transistors  

NASA Astrophysics Data System (ADS)

A SnO2 transparent thin-film transistor (TTFT) is demonstrated. The SnO2 channel layer is deposited by RF magnetron sputtering and then rapid thermal annealed in O2 at 600°C. The TTFT is highly transparent, and enhancement-mode behaviour is achieved by employing a very thin channel layer (10-20 nm). Maximum field-effect mobilities of 0.8 cm2 V-1 s-1 and 2.0 cm2 V-1 s-1 are obtained for enhancement- and depletion-mode devices, respectively. The transparent nature and the large drain current on-to-off ratio of 105 associated with the enhancement-mode behaviour of these devices may prove useful for novel gas-sensor applications.

Presley, R. E.; Munsee, C. L.; Park, C.-H.; Hong, D.; Wager, J. F.; Keszler, D. A.

2004-10-01

385

Growth process control of pentacene thin films and its application in full organic thin film transistors  

Microsoft Academic Search

Due to its outstanding carrier transport capabilities pentacene is a prominent candidate for the active semiconducting layer in organic thin film transistors. This compound crystallizes in a layered structure with herringbone arrangement within each layer. Pcntacene appears in several polymorphic structures, which differ basically by their c-axis lengths, meaning that the angle at which the molecules adsorb relative to the

U. Haa; Anja Haase; Hannes Maresch; Barbara Stadlober; Gijnter Leising

2004-01-01

386

Pulsed Laser Deposition of Epitaxial Topological Insulator Thin Films: Bi2Te3 and Bi2Te2Se  

NASA Astrophysics Data System (ADS)

While high quality epitaxial thin films of topological insulators have been achieved by molecular beam epitaxy, there has been little progress using other thin film growth techniques. Here, we report the growth of high quality epitaxial Bi2Te3 and Bi2Te2Se thin films on silicon (111) and YSZ (111) substrates by pulsed laser deposition (PLD). Systematic structural characterization of the films using x-ray diffraction and transmission electron microscopy has demonstrated that a low laser pulse rate is the key to achieving high quality epitaxial films. Rutherford backscattering spectrometry measurements suggest that the film composition is strongly influenced by the growth temperature and background gas pressure. The electrical transport properties of the films grown at the optimal conditions will also be discussed. Since PLD is an excellent tool to grow a variety of functional oxides, including multiferroics, magnetic semiconductors and high temperature superconductors, the growth of epitaxial topological insulator thin films by the same technique paves the way to synthesize multi-layered heterostructures of the above materials and search for novel physics arising from the resulting interfacial couplings.

Zhang, Shixiong; Yan, Li; Qi, Jingbo; Zhuo, Mujin; Wang, Yongqiang; Prasankumar, Rohit P.; Jia, Quanxi; Picraux, S. Tom

2012-02-01

387

TEM characterization of nanodiamond thin films.  

SciTech Connect

The microstructure of thin films grown by microwave plasma-enhanced chemical vapor deposition (MPCVD) from fullerene C{sub 60} precursors has been characterized by scanning electron microscopy (SEM), selected-area electron diffraction (SAED), bright-field electron microscopy, high-resolution electron microscopy (HREM), and parallel electron energy loss spectroscopy (PEELS). The films are composed of nanosize crystallites of diamond, and no graphitic or amorphous phases were observed. The diamond crystallite size measured from lattice images shows that most grains range between 3-5 nm, reflecting a gamma distribution. SAED gave no evidence of either sp2-bonded glassy carbon or sp3-bonded diamondlike amorphous carbon. The sp2-bonded configuration found in PEELS was attributed to grain boundary carbon atoms, which constitute 5-10% of the total. Occasionally observed larger diamond grains tend to be highly faulted.

Qin, L.-C.; Zhou, D.; Krauss, A. R.; Gruen, D. M.; Chemistry

1998-05-01

388

Ferroelectricity in hafnium oxide thin films  

NASA Astrophysics Data System (ADS)

We report that crystalline phases with ferroelectric behavior can be formed in thin films of SiO2 doped hafnium oxide. Films with a thickness of 10 nm and with less than 4 mol. % of SiO2 crystallize in a monoclinic/tetragonal phase mixture. We observed that the formation of the monoclinic phase is inhibited if crystallization occurs under mechanical encapsulation and an orthorhombic phase is obtained. This phase shows a distinct piezoelectric response, while polarization measurements exhibit a remanent polarization above 10 ?C/cm2 at a coercive field of 1 MV/cm, suggesting that this phase is ferroelectric. Ferroelectric hafnium oxide is ideally suited for ferroelectric field effect transistors and capacitors due to its excellent compatibility to silicon technology.

Böscke, T. S.; Müller, J.; Bräuhaus, D.; Schröder, U.; Böttger, U.

2011-09-01

389

Low temperature OMCVD of thin rhodium films  

SciTech Connect

Thin, highly reflective rhodium films with metal compositions greater than 98% (elemental weight percentage) have been deposited by chemical vapor deposition using Rh(allyl){sub 3} (allyl = {eta}{sup 3}-C{sub 3}H{sub 5}) in the presence of a hydrogen plasma. Uniform, crystalline films that adhere well to several types of substrates result from depositions at temperatures as low as 150{degrees}C. Depositions using H{sub 2} (no plasma), or an argon plasma yields material that is amorphous, contains a significant amount (>14%) of residual carbon, and has a dramatically slower growth rate. The composition of these materials does not vary significantly from that of the materials obtained from the in vacuo thermal deposition with Rh(allyl){sub 3}. 23 refs.

Laia, J.R.; Sattelberger, A.P.; Smith, D.C. (Los Alamos National Lab., NM (United States)); DeSantis, J.C. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering)

1992-01-01

390

High Performance Airbrushed Organic Thin Film Transistors  

SciTech Connect

Spray-deposited poly-3-hexylthiophene (P3HT) transistors were characterized using electrical and structural methods. Thin-film transistors with octyltrichlorosilane treated gate dielectrics and spray-deposited P3HT active layers exhibited a saturation regime mobility as high as 0.1 cm{sup 2} V{sup -1} s{sup -1}, which is comparable to the best mobilities observed in high molecular mass P3HT transistors prepared using other methods. Optical and atomic force microscopy showed the presence of individual droplets with an average diameter of 20 {micro}m and appreciable large-scale film inhomogeneities. Despite these inhomogeneities, near-edge x-ray absorption fine structure spectroscopy of the device-relevant channel interface indicated excellent orientation of the P3HT.

Chan, C.; Richter, L; Dinardo, B; Jaye, C; Conrad, B; Ro, H; Germack, D; Fischer, D; DeLongchamp, D; Gunlach, D

2010-01-01

391

Laser Ablation and Thin Film Deposition  

NASA Astrophysics Data System (ADS)

One of the most versatile deposition techniques in solid-state physics and analytical chemistry is the vaporization of condensed matter using photons. A short-pulsed high-power laser beam is focused onto a sample surface thereby converting a finite volume of a solid instantaneously into its vapor phase constituents such as ions and neutrals. Subsequently, the vapor moves away from the target at a high velocity and can be sampled either to grow a film or being analyzed by various spectroscopic techniques. In this chapter, the focus is on general properties of pulsed laser ablation relevant for solid-state physics like the initial ablation processes, plume formation, and plume properties. Next, oxide thin film growth will be discussed and the growth of LaAlO3/SrTiO3 heterostructures is presented as one example of tailoring oxide interfaces with surprising properties. The final discussion is on the topic of polymer ablation.

Schneider, Christof W.; Lippert, Thomas

392

Deposition of complex multielemental thin films  

NASA Astrophysics Data System (ADS)

Modern condensed-matter physics is increasingly concerned with the design, synthesis, analysis, and exploitation of chemically complex materials and structures. Complex metal oxides and strongly correlated electron systems such as YBa2Cu3O7-x and La1-xSrxMnO3 are paradigmatic examples. Their production in the form of high-quality thin films is of both technological and fundamental importance and has stimulated a concerted effort in the last two decades to find and optimize efficient techniques to this end. This review discusses the physics behind and the requirements for synthesizing high-quality films of such materials and examines fundamental aspects of the growth processes associated with magnetron sputtering and pulsed laser deposition, the two techniques which presently offer the best solutions in this burgeoning field.

Willmott, P. R.

2004-10-01

393

Thermal conductivity of amorphous carbon thin films  

SciTech Connect

Thermal conductivities {Lambda} of amorphous carbon thin films are measured in the temperatures range 80--400 K using the 3{omega} method. Sample films range from soft a-C:H prepared by remote-plasma deposition ({Lambda}=0.20 Wm{sup -1} K{sup -1} at room temperature) to amorphous diamond with a large fraction of sp{sup 3} bonded carbon deposited from a filtered-arc source ({Lambda}=2.2 Wm{sup -1} K{sup -1}). Effective-medium theory provides a phenomenological description of the variation of conductivity with mass density. The thermal conductivities are in good agreement with the minimum thermal conductivity calculated from the measured atomic density and longitudinal speed of sound.

Bullen, Andrew J.; O'Hara, Keith E.; Cahill, David G.; Monteiro, Othon; von Keudell, Achim

2000-12-01

394

Genetic algorithm and thin-film design  

NASA Astrophysics Data System (ADS)

Genetic algorithms, developed by J. H. Holland, are randomized search algorithms which mimic the mechanics of natural selection and natural genetics. In this work a genetic algorithm was applied to optimization of sophisticated thin-film systems. It was found to be an efficient tool rapidly converging to the target as defined by the merit function. The algorithm is introduced, discussed, and illustrated for two applications: a polarization-preserving coating of a penta-roof prism for a long-grange optical sight and a phase light splitter--beam divider/combiner for bi-directional fringe-counting interferometers.

Rabinovitch, Kopel; Toker, Gregory

1994-09-01

395

Thin film photovoltaic device with multilayer substrate  

DOEpatents

A thin film photovoltaic device which utilizes at least one compound semiconductor layer chosen from Groups IIB and VA of the Periodic Table is formed on a multilayer substrate The substrate includes a lowermost support layer on which all of the other layers of the device are formed. Additionally, an uppermost carbide or silicon layer is adjacent to the semiconductor layer. Below the carbide or silicon layer is a metal layer of high conductivity and expansion coefficient equal to or slightly greater than that of the semiconductor layer.

Catalano, Anthony W. (Rushland, PA); Bhushan, Manjul (Wilmington, DE)

1984-01-01

396

Progress in thin film CIGS modules  

SciTech Connect

We have demonstrated 13{percent} conversion efficiency in 40cm{sup 2} submodules based on CIGS. We review the developments that have made this possible, and identify several remaining areas where better understanding or further improvement would have a significant effect on the commercial viability of large area thin film modules based on CIGS. We report some recent results in these remaining areas, specifically on the achievement of larger area deposition for the absorber layer, the achievement of highly conductive ZnO, and some results on the function of the buffer and contacting layers in the CIGS based structure. {copyright} {ital 1997 American Institute of Physics.}

Wiedeman, S.; Kessler, J.; Russell, L.; Fogleboch, J.; Skibo, S.; Arya, R. [Solarex (A business unit of Amoco/Enron Solar) 826 Newtown-Yardley Road, Newtown, Pennsylvania 18940 (United States)

1997-02-01

397

Active Chiral Processes in Thin Films  

NASA Astrophysics Data System (ADS)

We develop a generic description of thin active films that captures key features of flow and rotation patterns emerging from the activity of chiral motors which introduce torque dipoles. We highlight the role of the spin rotation field and show that fluid flows can occur in two ways: by coupling of the spin rotation rate to the velocity field via a surface or by spatial gradients of the spin rotation rate. We discuss our results in the context of patches of bacteria on solid surfaces and groups of rotating cilia. Our theory could apply to active chiral processes in the cell cytoskeleton and in epithelia.

Fürthauer, S.; Strempel, M.; Grill, S. W.; Jülicher, F.

2013-01-01

398

Arizona State University: Surfaces and Thin Films  

NSDL National Science Digital Library

At this website, John Venables at Arizona State University offers chemistry students lecture notes about surface and thin film processes. After reading the introduction to surface processes, users can find more in-depth materials on surfaces in vacuums, techniques for examining surfaces, electric and magnetic processes, surface processes in epitaxial growth, and much more. Each main chapter contains figures and problems to help users understand the complicated concepts. This site can be a great addition to a textbook and formal class for chemistry students.

399

Giant magnetocaloric effect of thin Ho films  

NASA Astrophysics Data System (ADS)

We report a theoretical study of the impact of finite size on the magnetocaloric effect (MCE) of thin Ho films. For strong external field strengths, the adiabatic temperature change ?Tad is comparable to the value found in bulk Ho, reaching about 12 K for an external field strength change ?H = 50 kOe. For thicknesses below the helix period, there is a large enhancement. In this thickness range, the helical state does not form, leading to a giant MCE reaching ?T/?H = 6.5 K/T for ?H = 2 kOe.

Filho, F. C. Medeiros; Mello, V. D.; Dantas, A. L.; Sales, F. H. S.; Carriço, A. S.

2011-04-01

400

Laser scribing of polycrystalline thin films  

Microsoft Academic Search

We have investigated the use of several different types of lasers for scribing of the polycrystalline materials used for thin-film solar cells: CdTe, CuInGaSe2 (CIGS), ZnO, SnO2, Mo, Al, and Au. The lasers included four different neodymium–yttrium–aluminum garnet (Nd:YAG) (both 1064 and 532nm wavelengths), a Cu vapor (511\\/578nm), an XeCl excimer (308nm), and a KrF excimer (248nm). Pulse durations ranged

A. D Compaan; I. Matulionis; S. Nakade

2000-01-01

401

Laser deposition and laser modification of high-temperature superconducting thin films  

SciTech Connect

Applications of high-temperature superconductors (HTSC) may require epitaxial films with {Tc}{ge}77 K, and J{sub c}{ge}10{sup 6} A/cm{sup 2}. In situ pulsed laser deposition (PLD) is suitable for fabrication of such films. We report parametric studies on the effect of laser and processing parameters on the crystallinity, epitaxy and electrical properties of laser-deposited HTSC thin films. In addition, several laser-based processes were used to modify the electrical properties ({Tc} and J{sub c}) of PLD thin films. A direct-write laser heating (1.06 {mu}m at {approx}0.5 kW/cm{sup 2} for {approx}5 min) process in an oxygen atmosphere at {approx}590 Torr was shown to selectivity regenerate high-{Tc} material in microscopic domains from films that were partially deoxygenated. In separate work, electrical responses and crystallinity of HTSC films were measured as a function of excimer laser exposure using fluences in the range 20--150 mJ/cm{sup 2}. The critical current and boundary layer could be modified with a high degree of accuracy. 17 refs., 4 figs.

Dye, R.C.; Foltyn, S.R.; Nogar, N.S.; Wu, X.D.; Peterson, E.J.; Muenchausen, R.E.

1991-01-01

402

Fabrication of ZnO thin film transistors by atomic force microscopy nanolithogrophy through zinc thin films  

NASA Astrophysics Data System (ADS)

Zinc oxide (ZnO) thin film transistors were fabricated by local anodic oxidation (LAO) of polycrystalline zinc film using an atomic force microscope (AFM). Nanometer-thin zinc film can be locally transformed into p -type zinc oxide by an anodic oxidation technique using an AFM at room temperature. With this fabrication process, we have fabricated a backgate, Schottky-barrier-contact type thin film ZnO transistor. This fabrication requires no semiconductor material to produce transistors, only conventional metal film. The fabrication creates active area and source/drain contacts through simple AFM oxidation, with no requirement for additional semiconductor thin film deposition and photolithography. A representative LAO thin film transistor fabricated in this study exhibited a field-effect mobility of 23.6cm2/Vs , a peak transconductance of 15.8?S , and an Ion/Ioff ratio of 106 . To the best of our knowledge, the mobility value attained for this LAO thin film transistor is higher than that of any previously reported amorphous-silicon-based thin film transistors. Its peak transconductance and Ion/Ioff ratio are also enhanced compared with a backgate field-effect transistor with the same amorphous silicon channel as utilized in conventional thin film transistors.

Tsai, Jeff T. H.; Lee, Ben H. B.; Yang, Ming S.

2009-12-01

403

Impedance spectroscopy of epitaxial multiferroic thin films  

NASA Astrophysics Data System (ADS)

Temperature dependent impedance spectroscopy enables the many contributions to the dielectric and resistive properties of condensed matter to be deconvoluted and characterized separately. We have achieved this for multiferroic epitaxial thin films of BiFeO3 (BFO) and BiMnO3 (BMO), key examples of materials with strong magnetoelectric coupling. We demonstrate that the true film capacitance of the epitaxial layers is similar to that of the electrode interface, making analysis of capacitance as a function of film thickness necessary to achieve deconvolution. We modeled non-Debye impedance response using Gaussian distributions of relaxation times and reveal that conventional resistivity measurements on multiferroic layers may be dominated by interface effects. Thermally activated charge transport models yielded activation energies of 0.60±0.05eV (BFO) and 0.25±0.03eV (BMO), which is consistent with conduction dominated by oxygen vacancies (BFO) and electron hopping (BMO). The intrinsic film dielectric constants were determined to be 320±75 (BFO) and 450±100 (BMO).

Schmidt, Rainer; Eerenstein, Wilma; Winiecki, Thomas; Morrison, Finlay D.; Midgley, Paul A.

2007-06-01

404

Thin film coatings with variable emittance  

NASA Astrophysics Data System (ADS)

The temperature of a nanosatellite in orbit varies strongly as it goes into earth shadow or solar radiation. A variable emittance panel built with an electrochromic material, could improve the temperature control by providing an adaptive thermal control. The active function is due to an electrochromic layer, WO3, deposited by sputtering. Intercalation of Li+ leads to a change in the electron configuration, which modulates the radiation properties. Thin WO3 films were deposited onto Indium Tin Oxide (ITO) coated glass by reactive dc sputtering. IR measurements were done in a Perkin-Elmer 983 spectrophotometer. The IR emittance modulation, (Delta) (epsilon) of WO3 films, deposited on ITO coated glass, has been investigated. The emittance, (epsilon) , is computed from the reflectance, at 25 degrees C. Initial results show emittances in the range from 0.2 to 0.5 crystalline film has (Delta) (epsilon) equals 0.12, and the amorphous film has (Delta) (epsilon) equals 0.3. IR properties of WO3 need to be further investigated as well as the construction of a whole device.

Larsson, Anna-Lena; Niklasson, Gunnar A.; Stenmark, Lars

1999-09-01

405

Orientation-dependent critical currents in Y sub 1 Ba sub 2 Cu sub 3 O sub 7-x epitaxial thin films: Evidence for intrinsic flux pinning  

SciTech Connect

For YBCO epitaxial thin films the basal plane transport critical current density J{sub c}, flowing perpendicular to an applied magnetic field H, depends sensitively on the orientation of the crystal with respect to H. In particular, J{sub c} is sharply peaked and greatly enhanced when H is precisely parallel to the copper-oxygen planes. Experiments on a series of epitaxial monolithic and superconductor-insulator multilayer thin films provide clear evidence that the enhancement is a bulk, rather than surface or thin sample, phenomenon. Measurements of the orientation dependence are presented and compared with a model of intrinsic flux pinning'' by the layered crystal structure.

Christen, D.K.; Klabunde, C.E.; Feenstra, R.; Lowndes, D.H.; Norton, D.P.; Budai, J.D.; Kerchner, H.R.; Thompson, J.R.; Zhu, S. (Oak Ridge National Lab., TN (USA)); Marwick, A.D. (Thomas J. Watson Research Center, Yorktown Heights, NY (USA))

1990-01-01

406

Electrical, morphological and structural properties of RF magnetron sputtered Mo thin films for application in thin film photovoltaic solar cells  

Microsoft Academic Search

Molybdenum (Mo) thin films were deposited using radio frequency magnetron sputtering, for application as a metal back contact\\u000a material in “substrate configuration” thin film solar cells. The variations of the electrical, morphological, and structural\\u000a properties of the deposited films with sputtering pressure, sputtering power and post-deposition annealing were determined.\\u000a The electrical conductivity of the Mo films was found to increase

Guillaume ZoppiNeil; Neil S. Beattie; Jonathan D. Major; Robert W. Miles; Ian Forbes

2011-01-01

407

HREM investigation of (110) oriented YBa2Cu3O7 thin films deposited on (110) SrTiO3 substrates  

Microsoft Academic Search

The epitaxial growth and microstructure of YBa2Cu3O7 thin films on (110) SrTiO3 substrates was investigated by high-resolution electron microscopy. The single thin films and heterostructures with PrBa2Cu3O7 and SrTiO3 separating the superconductor layers were deposited by DC sputtering. All layers were grown with the [110] direction perpendicular to the substrate surface with the c-axis of the YBa2Cu3O7 film oriented parallel

J. W. Seo; B. Kabius; C. L. Jia; H. Soltner; U. Poppe; K. Urban

1994-01-01

408

Studies on superconducting thin films for SRF applications  

SciTech Connect

In order to overcome the fundamental limit of Nb's critical magnetic field ({approx} 200 mT) that corresponds to E{sub acc} {approx}50 MV/m, an idea of coating several thin layers of a superconductor has been proposed. MgB{sub 2}, a superconductor that has a T{sub c} of {approx}39 K, has been studied to explore the effect of coating in terms of DC and RF critical magnetic fields, and RF surface losses. MgB{sub 2} has shown an excellent behavior, although there is some discrepancy between DC and RF measurements.

Tajima, Tsuyoshi [Los Alamos National Laboratory; Haberkorn, Nestor [Los Alamos National Laboratory; Civale, Leonardo [Los Alamos National Laboratory; Hawley, Marilyn [Los Alamos National Laboratory; Schulze, Roland [Los Alamos National Laboratory; Zocco, Adam [Los Alamos National Laboratory; Eremeev, Grigory [TJNAF; Guo, Jiquan [SLAC; Dolgashev, Valery [SLAC; Martin, David [SLAC; Tantawi, Sami [SLAC; Yoneda, Charles [SLAC; Doi, Toshiya [KAGOSHIMA UNIV.; Matsumoto, Akiyoshi [NIMS

2010-09-09

409

The role of microstructural phenomena in magnetic thin films  

SciTech Connect

The subject is germane to magnetic recording media. Results during the first 2 years are presented under the following headings: atomic resolution TEM of CoNiCr films; CoNiCr and CoCrTa thin films; development of texture; and CoSm/Cr thin films. The HREM results showed that defects in Co-based films may be responsible for higher coercivity. Findings are presented on the effects of Cr interlayers on the microstructure of the second Co-based film in Co/Cr/Co/Cr multilayer films. Proposed research plans are outlined.

Laughlin, D.E.; Lambeth, D.N.

1992-01-01

410

The role of microstructural phenomena in magnetic thin films  

SciTech Connect

The subject is germane to magnetic recording media. Results during the first 2 years are presented under the following headings: atomic resolution TEM of CoNiCr films; CoNiCr and CoCrTa thin films; development of texture; and CoSm/Cr thin films. The HREM results showed that defects in Co-based films may be responsible for higher coercivity. Findings are presented on the effects of Cr interlayers on the microstructure of the second Co-based film in Co/Cr/Co/Cr multilayer films. Proposed research plans are outlined.

Laughlin, D.E.; Lambeth, D.N.

1992-12-31

411

Zinc Oxide Transparent Thin Films For Optoelectronics  

NASA Astrophysics Data System (ADS)

The object of this body of work is to study the properties and suitability of zinc oxide thin films with a view to engineering them for optoelectronics applications, making them a cheap and effective alternative to indium tin oxide (ITO), the most used transparent conducting oxides in the industry. Initially, a study was undertaken to examine the behavior of silver contacts to ZnO and ITO during thermal processing, a step frequently used in materials processing in optoelectronics. The second study involved an attempt to improve the conductivity of ZnO films by inserting a thin copper layer between two ZnO layers. The Hall resistivity of the films was as low as 6.9x10 -5 O-cm with a carrier concentration of 1.2x10 22 cm-3 at the optimum copper layer thickness. The physics of conduction in the films has been examined. In order to improve the average visible transmittance, we replaced the copper layer with gold. The films were then found to undergo a seven orders of magnitude drop in effective resistivity from 200 O-cm to 5.2x10-5 O-cm The films have an average transmittance between 75% and 85% depending upon the gold thickness, and a peak transmittance of up to 93%. The best Haacke figure of merit was 15.1x10-3 O-1. Finally, to test the multilayer transparent electrodes on a device, ZnO/Au/ZnO (ZAZ) electrodes were evaluated as transparent electrodes for organic light-emitting devices (OLEDs). The electrodes exhibited substantially enhanced conductivity (about 8x10-5 O-cm) over conventional indium tin oxide (ITO) electrodes (about 3.2x10-5 O-cm). OLEDs fabricated with the ZAZ electrodes showed reduced leakage compared to control OLEDs on ITO and reduced ohmic losses at high current densities. At a luminance of 25000 cd/m2, the lum/W efficiency of the ZAZ electrode based device improved by 5% compared to the device on ITO. A normalized intensity graph of the colour output from the green OLEDs shows that ZAZ electrodes allow for a broader spectral output in the green wavelength region of peak photopic sensitivity compared to ITO. The results have implications for electrode choice in display technology.

Sivaramakrishnan, Karthik

412

Optical thin film metrology for optoelectronics  

NASA Astrophysics Data System (ADS)

The manufacturing of optoelectronic thin films is of key importance, because it underpins a significant number of industries. The aim of the European joint research project for optoelectronic thin film characterization (IND07) in the European Metrology Research Programme of EURAMET is to develop optical and X-ray metrologies for the assessment of quality as well as key parameters of relevant materials and layer systems. This work is intended to be a step towards the establishment of validated reference metrologies for the reliable characterization, and the development of calibrated reference samples with well-defined and controlled parameters. In a recent comprehensive study (including XPS, AES, GD-OES, GD-MS, SNMS, SIMS, Raman, SE, RBS, ERDA, GIXRD), Abou-Ras et al. (Microscopy and Microanalysis 17 [2011] 728) demonstrated that most characterization techniques have limitations and bottle-necks, and the agreement of the measurement results in terms of accurate, absolute values is not as perfect as one would expect. This paper focuses on optical characterization techniques, laying emphasis on hardware and model development, which determine the kind and number of parameters that can be measured, as well as their accuracy. Some examples will be discussed including optical techniques and materials for photovoltaics, biosensors and waveguides.

Petrik, Peter

2012-12-01

413

Dynamic interfaces in an organic thin film  

PubMed Central

Low-dimensional boundaries between phases and domains in organic thin films are important in charge transport and recombination. Here, fluctuations of interfacial boundaries in an organic thin film, acridine-9-carboxylic acid on Ag(111), have been visualized in real time and measured quantitatively using scanning tunneling microscopy. The boundaries fluctuate via molecular exchange with exchange time constants of 10–30 ms at room temperature, with length-mode fluctuations that should yield characteristic f?1/2 signatures for frequencies less than ?100 Hz. Although acridine-9-carboxylic acid has highly anisotropic intermolecular interactions, it forms islands that are compact in shape with crystallographically distinct boundaries that have essentially identical thermodynamic and kinetic properties. The physical basis of the modified symmetry is shown to arise from significantly different substrate interactions induced by alternating orientations of successive molecules in the condensed phase. Incorporating this additional set of interactions in a lattice–gas model leads to effective multicomponent behavior, as in the Blume–Emery–Griffiths model, and can straightforwardly reproduce the experimentally observed isotropic behavior. The general multicomponent description allows the domain shapes and boundary fluctuations to be tuned from isotropic to highly anisotropic in terms of the balance between intermolecular interactions and molecule–substrate interactions.

Tao, Chenggang; Liu, Qiang; Riddick, Blake C.; Cullen, William G.; Reutt-Robey, Janice; Weeks, John D.; Williams, Ellen D.

2008-01-01

414

Use of thin films in high-temperature superconducting bearings.  

SciTech Connect

In a PM/HTS bearing, locating a thin-film HTS above a bulk HTS was expected to maintain the large levitation force provided by the bulk with a lower rotational drag provided by the very high current density of the film. For low drag to be achieved, the thin film must shield the bulk from inhomogeneous magnetic fields. Measurement of rotational drag of a PM/HTS bearing that used a combination of bulk and film HTS showed that the thin film is not effective in reducing the rotational drag. Subsequent experiments, in which an AC coil was placed above the thin-film HTS and the magnetic field on the other side of the film was measured, showed that the thin film provides good shielding when the coil axis is perpendicular to the film surface but poor shielding when the coil axis is parallel to the surface. This is consistent with the lack of reduction in rotational drag being due to a horizontal magnetic moment of the permanent magnet. The poor shielding with the coil axis parallel to the film surface is attributed to the aspect ratio of the film and the three-dimensional nature of the current flow in the film for this coil orientation.

Hull, J. R.; Cansiz, A.

1999-09-30

415

Polycrystalline Thin-Film Photovoltaic Technologies: Progress and Technical Issues.  

National Technical Information Service (NTIS)

Polycrystalline thin-film materials based on copper indium diselenide (CuInSe2, CIS) and cadmium telluride (CdTe) are promising thin-film solar cells for various power and specialty applications. Impressive results have been obtained in the past few years...

H. S. Ullal

2004-01-01

416

Microchannel membrane separation applied to confined thin film desorption  

Microsoft Academic Search

The concept of a confined thin film to enhance the desorption process is based on a reduced mass diffusion resistance. A wide thin film is formed into a microchannel by using a porous membrane as one wall of the channel enabling vapor extraction along the flow. Heat added to the channel results in vapor generation and subsequent extraction through the

Jonathan D. Thorud; James A. Liburdy; Deborah V. Pence

2006-01-01

417

Texture control of fluorine-doped tin oxide thin film  

Microsoft Academic Search

The texture control of transparent oxide thin film, the crystalline orientation, is very important, because it is related to the electrical resistivity and the optical transparency. It is known that the crystal orientation could be controlled by varying precursor source, gas flow rate, and deposition temperature. We deposited fluorine-doped tin oxide (FTO) thin film on aluminoborosilicate glass by spraying water-based

Chang-Yeoul Kim; Doh-Hyung Riu

2011-01-01

418

Nanoscale surface modification of thin film microelectrodes to improve biocompatibility  

Microsoft Academic Search

The promise of multichannel thin film microelectrodes for closed-loop neural prosthetic control has been hindered by the inability of these electrodes to record for long periods of time. Recently, we have shown that thin film electrodes produced using a ceramic substrate and insulation (CBMSE arrays) can consistently record single neuron action potentials for three months in the rat, which is

Brian C. DiPaolo; Jen Liu; Carrie Mohila; Karen A. Moxon

2002-01-01

419

Hot phonon spot formation and dynamics in the thin film.  

National Technical Information Service (NTIS)

The hot phonon spot formation and development in the thin semiconductor film as a result of photoexcited current carriers cooling is discussed. The film is assumed to be thin enough so that thickness d follows d/(upsilon) << (eta)((omega)), where (nu) - i...

F. F. Agaev N. M. Guseinov K. A. Rustamov

1992-01-01

420

Interfacial toughness measurements for thin films on substrates  

Microsoft Academic Search

There are more than 200 different methods for measuring adhesion, suggesting it to be material, geometry and even industry specific. This availability has exploded at least partly due to the arrival of dissimilar material interfaces and thin films and the ease with which microfabrication techniques apply to silicon technology. Having an eye toward those tests utilized for thin films, this

A. A. Volinsky; N. R. Moody; W. W. Gerberich

2002-01-01

421

Simulations of microdomain lattice defects in block copolymer thin films  

Microsoft Academic Search

In this dissertation we discuss three studies of microdomain ordering in block copolymer thin films. In the first study we report on two new numerical techniques for removing metastable microdomain defects that can be used in field-theoretic computer simulations of block copolymer thin films: (1) a spectral amplitude filter (SF) which encourages the simulation to relax into high symmetry states

August W. Bosse

2006-01-01

422

Electrocaloric devices based on thin-film heat switches  

Microsoft Academic Search

We describe a new approach to refrigeration, heat pumping, and electrical generation that allows one to exploit the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators and heat pumps or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches

Richard I. Epstein; Kevin J. Malloy

2009-01-01

423

Structure and electrical conduction properties of phthalocyanine thin films  

Microsoft Academic Search

The structure and the dc and ac electrical conduction properties of evaporated phthalocyanine thin films are critically reviewed.Results of various structural studies on phthalocyanine single crystals and thin films performed using X-ray diffraction methods are described, and reported unit cell dimensions are given for several phthalocyanines in both the metastable ? and the stable ? forms: reported unit cell dimensions

R. D. Gould

1996-01-01

424

TEM studies of RF magnetron-sputtered thin films  

Microsoft Academic Search

Lead scandium tantalate (PST) thin films sputtered onto sapphire substrates have been studied by using transmission electron microscopy. Samples in transverse section were used to characterize the microstructure of the thin films as a function of distance from the PST-sapphire interface whereas samples in plan section allowed a more detailed, structural investigation of the PST. A liquid nitrogen cold stage

I. M. Reaney; D. J. Barber; R. Watton

1992-01-01

425

The Chemical Vapor Deposition of Thin Metal Oxide Films  

Microsoft Academic Search

Chemical vapor deposition (CVD) is an important method of preparing thin films of materials. Copper (II) oxide is an important p-type semiconductor and a major component of high T_{rm c} superconducting oxides. By using a volatile copper (II) chelate precursor, copper (II) bishexafluoroacetylacetonate, it has been possible to prepare thin films of copper (II) oxide by low temperature normal pressure

Angus Buchanan Laurie

1990-01-01

426

EXPERIMENTAL STUDY OF THIN LIQUID FILM ULTRASONIC ATOMIZATION  

Microsoft Academic Search

Ultrasonic atomization of liquids results from the unstable surface waves generated at the level of the thin liquid film that forms as the liquid spreads over the atomizing surface. This work continues our experimental analysis of both the thin liquid film disintegration phenomena and the ultrasonic atomizer sprays. The unstable surface waves, which are responsible for the droplets formation, are

D. Sindayihebura; M. Dobre; L. Bolle

427

A new micro SMA thin film actuator prestrained by polyimide  

Microsoft Academic Search

Micro SMA (shape memory alloy) thin film is a good material for a microactuator of a micromachine on silicone wafer, because of it merits: i) low driving voltage, ii) big force per volume and weight, iii) faster response compared to bulk SMA actuator. However there is a problem in fabricating micro SMA thin film actuator on silicone wafer; that is,

Katsutoshi Kuribayashi; T. Fujii

1998-01-01

428

New definition of laser damage threshold of thin film  

Microsoft Academic Search

The mechanism of laser-induced damage to thin films is described and a definition of laser breakdown threshold to thin film, and optical breakdown threshold, is presented. The new definition is clearer than the existing one. The measurement results and comparison for various samples are given on the basis of the two above-mentioned definitions.

Xiao-Wu Ni; Jian-Feng Lu; An-Zhi He; Zi Ma; Jiu L. Zhou

1991-01-01

429

Tools to Synthesize the Learning of Thin Films  

ERIC Educational Resources Information Center

|After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase…

Rojas, Roberto; Fuster, Gonzalo; Slusarenko, Viktor

2011-01-01

430

Deposition and characterization of nichrome thin film over PDMS elastomer  

Microsoft Academic Search

Nichrome (Ni - Cr 80\\/20 wt.%) is one of the most widely used thin film material for the development of micro heaters in various applications. Present paper discusses the optimized sputtering conditions required for successful deposition of nichrome thin film and fabrication of microheaters over a biocompatible polymer PDMS, for biomedical application. Various sputtering conditions like the base vacuum, working

Debashis Maji; Puneet Manocha; Soumen Das

2010-01-01

431

Roll-to-roll manufacturing of thin film electronics  

Microsoft Academic Search

The development and current status of roll-to-roll manufacturing processes and equipment relevant to the fabrication of patterned, active electronic devices such as thin film transistors (TFTs) is reviewed, along with a survey of the knowledge of processing for thin film electronics on flexible (especially polymer) substrates. It is concluded that while there are a number of unknowns and engineering challenges,

James R. Sheats

2002-01-01

432

Interface engineered multifunctional oxide thin films with optimized properties  

Microsoft Academic Search

In our world today, energy has become one of the most valuable resources, in particular, renewable and clean energy sources. The research presented here represents an investigation into three separate areas of this topic. In thin film applications, the ordered structures as well as the inherent thinness of the films precludes the normal physics found in bulk materials. Characterizations of

Gregory Roy Collins

2010-01-01

433

Femtosecond pulsed laser deposition of silicon thin films  

NASA Astrophysics Data System (ADS)

Optimisation of femtosecond pulsed laser deposition parameters for the fabrication of silicon thin films is discussed. Substrate temperature, gas pressure and gas type are used to better understand the deposition process and optimise it for the fabrication of high-quality thin films designed for optical and optoelectronic applications.

Murray, Matthew; Jose, Gin; Richards, Billy; Jha, Animesh

2013-06-01

434

Microfocusing optical device using piezoelectric thin-film actuator  

Microsoft Academic Search

A novel micro focusing optical device controlled by a piezoelectric thin film micro actuator has been presented. This device is provided by bonding two micromachined substrates, which are a glass substrate integrated with a surface emitting light element and a micro Fresnel lens on each surface, and a silicon substrate with a diaphragm type of piezoelectric thin film actuator on

Hiroshi Goto; Shyuichi Wakabayashi; Masaaki Ikeda; Minoru Sakata; Koichi Imanaka; Masashi Takeuchi; Tuneji Yada

1995-01-01

435

Preparation of highly textured surface ZnO thin films  

Microsoft Academic Search

In order to investigate the influence of the deposition technique upon the surface morphology of ZnO thin films we have employed two methods, which are the spray pyrolysis and magnetron sputtering. The surface morphology of ZnO thin films is a crucial parameter for controlling the reflection losses reduction when the coating is used as a transparent front layer in solar

A. Mosbah; S. Abed; N. Bouhssira; M. S. Aida; E. Tomasella

2006-01-01

436

NbN thin films for superconducting radio frequency cavities  

NASA Astrophysics Data System (ADS)

NbN thin films have the potential to be incorporated into radio frequency cavities in a multilayer coating to overcome the fundamental field gradient limit of 50 MV m-1 for the bulk niobium based technology that is currently implemented in particle accelerators. In addition to having a larger critical field value than bulk niobium, NbN films develop smoother surfaces which are optimal for cavity performance and lead to fewer losses. Here, we present a study on the correlation of film deposition parameters, surface morphology, microstructure, transport properties and superconducting properties of NbN thin films. We have achieved films with bulk-like lattice parameters and superconducting transition temperatures. These NbN films have a lower surface roughness than similarly grown niobium films of comparable thickness. The potential application of NbN thin films in accelerator cavities is discussed.

Roach, W. M.; Skuza, J. R.; Beringer, D. B.; Li, Z.; Clavero, C.; Lukaszew, R. A.

2012-12-01

437

Thickness dependence of conduction currents in ultra thin evaporated polypropylene films  

Microsoft Academic Search

A ultra thin polypropylene film (thin PP film) was deposited on a glass substrate by the vacuum evaporation method. A thin PP film deposited on a glass substrate at room temperature was annealed for one hour in N2. Thin PP films are about 60~1.50 A in thickness. Aluminum electrodes (2 mm square) were evaporated on both sides of a thin

S. Ochiai; T. Kato; T. Ogawa; K. Kojima; Y. Uchida; A. Ohashi; M. Ieda; T. Mizutani

1994-01-01

438

Information-bearing structures and magnetism of thin films. Annual report, 1997--1998  

SciTech Connect

Progress is reported on the following: theory of Skyrmions in magnetic films; hystersis in thin magnetic films; interaction of magnetic dots with superconducting films;and phase transformations in thin magnetic films.

Pokrovsky, V.L.; Saslow, W.M.

1998-06-01

439

Extending the 3? method: thermal conductivity characterization of thin films.  

PubMed

A lock-in technique for measurement of thermal conductivity and volumetric heat capacity of thin films is presented. The technique is based on the 3? approach using electrical generation and detection of oscillatory heat along a thin metal strip. Thin films are deposited onto the backside of commercial silicon nitride membranes, forming a bilayer geometry with distinct thermal parameters. Stepwise comparison to an adapted heat diffusion model delivers these parameters for both layers. Highest sensitivity is found for metallic thin films. PMID:24007093

Bodenschatz, Nico; Liemert, André; Schnurr, Sebastian; Wiedwald, Ulf; Ziemann, Paul

2013-08-01

440

Pulsed Laser Deposition of Nanoporous Cobalt Thin Films  

PubMed Central

Nanoporous cobalt thin films were deposited on anodized aluminum oxide (AAO) membranes at room temperature using pulsed laser deposition. Scanning electron microscopy demonstrated that the nanoporous cobalt thin films retained the monodisperse pore size and high porosity of the anodized aluminum oxide substrates. Temperature- and field-dependent magnetic data obtained between 10 K and 350 K showed large hysteresis behavior in these materials. The increase of coercivity values was larger for nanoporous cobalt thin films than for multilayered cobalt/alumina thin films. The average diameter of the cobalt nanograins in the nanoporous cobalt thin films was estimated to be ~5 nm for blocking temperatures near room temperature. These results suggest that pulsed laser deposition may be used to fabricate nanoporous magnetic materials with unusual properties for biosensing, drug delivery, data storage, and other technological applications.

Jin, Chunming; Nori, Sudhakar; Wei, Wei; Aggarwal, Ravi; Kumar, Dhananjay; Narayan, Roger J.

2013-01-01

441

Development of Thin-Film Battery Powered Transdermal Medical Devices  

SciTech Connect

Research carried out at ORNL has led to the development of solid state thin-film rechargeable lithium and lithium-ion batteries. These unique devices can be fabricated in a variety of shapes and to any required size, large or small, on virtually any type of substrate. Because they have high energies per unit of volume and mass and because they are rechargeable, thin-film lithium batteries have potentially many applications as small power supplies in consumer and special electronic products. Initially, the objective of this project was to develop thin-film battery powered products. Initially, the objective of this project was to develop thin-film battery powered transdermal electrodes for recording electrocardiograms and electroencephalograms. These ''active'' electrode would eliminate the effect of interference and improve the reliability in diagnosing heart or brain malfunctions. Work in the second phase of this project was directed at the development of thin-film battery powered implantable defibrillators.

Bates, J.B.; Sein, T.

1999-07-06

442

Ultra-thin gold films on transparent polymers  

NASA Astrophysics Data System (ADS)

Fabrication of continuous ultra-thin gold films (<10 nm) on the surface of optical polymers (CYCLOTENE and ORMOCLEAR) is reported. Using a range of electrical, optical and structural characterization techniques, we show that polymers can be superior to more conventional (inorganic) materials as optical substrates for realizing ultra-thin gold films. Using these transparent polymer substrates, smooth, patternable gold films can be fabricated with conventional deposition techniques at room temperature, without adhesion or seeding layers, facilitating new photonic and plasmonic nanostructures, including transparent electrical contacts, thin film waveguides, metamaterials, biosensors and high-contrast superlenses.

Leosson, Kristjan; Ingason, Arni S.; Agnarsson, Bjorn; Kossoy, Anna; Olafsson, Sveinn; Gather, Malte C.

2013-02-01

443

Method of producing solution-derived metal oxide thin films  

DOEpatents

A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

Boyle, Timothy J. (Albuquerque, NM); Ingersoll, David (Albuquerque, NM)

2000-01-01

444

REVIEW ARTICLE: Forces and structure in thin liquid soap films  

NASA Astrophysics Data System (ADS)

This review is a topical survey of the forces and structures in thin liquid soap films. Included is a description of both the more classical forces, such as electrostatic double-layer and dispersion forces, together with new and emerging areas of research that cover so-called `supramolecular' forces. This latter category covers self-assembly of macromolecular structures confined in a thin-film region together with surface-induced adsorption of macromolecular complexes. In addition, recent extensions of the relation between thin-film forces and film stability are reviewed.

Bergeron, Vance

1999-05-01

445

Synthesis and characterization of nanostructured ZnS thin film  

NASA Astrophysics Data System (ADS)

ZnS is a promising II-VI semiconductor with wide applications in optoelectronic devices. We report the synthesis of nanostructured ZnS thin film by chemical spray pyrolysis (CSP). Previous reports on ZnS thin films prepared by spray pyrolysis have been found to be of cubic structure at deposition temperatures below 500°C. Here we report the synthesis of ZnS thin film with hexagonal structure at a deposition temperature of 350°C. XRD result showed that the film was hexagonal in structure with average grain size 20nm. From the absorption studies the band gap was found to be 4.04eV.

Safeera, T. A.; Anju, K. J.; Joffy, P. J.; Anila, E. I.

2013-02-01

446

Chemical preparation of powders and films for high temperature superconductors  

Microsoft Academic Search

A precipitation process has been developed to prepare precursor powders which can be calcined and sintered to form high critical temperature superconductors such as YBa(sub 2)Cu(sub 3)O(sub 7-x). Precursor powders are prepared using a continuous precipitation system in which a solution containing highly soluble salts of the desired metal cations is rapidly and completely mixed with a solution containing precipitating

B. C. Bunker; J. A. Voigt; D. L. Lamppa; D. H. Doughty; E. L. Venturini; J. F. Kwak; D. S. Ginley; T. J. Headley; M. S. Harrington; M. O. Eatough

1988-01-01

447

Direct model for thin wetting film focusing  

NASA Astrophysics Data System (ADS)

We demonstrated that the use of thin wetting film focusing allows detection of single micrometer-size objects with 24 mm2 lensfree imaging. In order to refine the technique and push the detection limit down to the nanometer scale, a deep insight in the imaging mechanisms is necessary. We constructed a model based on wetting film microfluidics and Fresnel diffraction of light. This model properly fits the intensity measurements acquired on micro-particles with our lensfree imaging setup. When the particle diameter is 1 µm, a microlens is formed by a liquid surface deformation of about 100 nm in height over few microns radial distance. The measured point spread function of the light deflected by such microlens presents a constant beam intensity over a long range, between 50 µm and 250 µm from the object plane. This is very similar to what is obtained by illuminating an axicon with a Gaussian beam, i.e. the central beam propagates for several Rayleigh ranges without appreciable divergences. In the lensfree imaging setup, the detector plane is far apart from the object (?500 µm). Thus, it is a true advantage to form axicon lens that can propagate strong intensity beams up to the detector plane. Most important, our model predicts that the detection of smaller objetcs needs thinner films. These results are important for further detecting viruses with lensfree imaging techniques.

Migliozzi, D.; Allier, C. P.; Hennequin, Y.; Coutard, J.-C.; Dinten, J.-M.

2013-02-01

448

Phase Transitions in Thin Block Copolymer Films  

SciTech Connect

David Turnbull's experiments and theoretical insights paved the way for much of our modern understanding of phase transitions in materials. In recognition of his contributions, this lecture will concentrate on phase transitions in a material system not considered by Turnbull, thin diblock copolymer films. Well-ordered block copolymer films are attracting increasing interest as we attempt to extend photolithography to smaller dimensions. In the case of diblock copolymer spheres, an ordered monolayer is hexagonal, but the ordered bulk is body-centered cubic (bcc). There is no hexagonal plane in the bcc structure, so a phase transition must occur as n, the number of layers of spheres in the film, increases. How this phase transition occurs with n and how it can be manipulated is the subject of the first part of my presentation. In the second part of the talk, I show that monolayers of diblock copolymer spheres and cylinders undergo order-to-disorder transitions that differ greatly from those of the bulk. These ordered 2D monolayers are susceptible to phonon-generated disorder as well as to thermal generation of defects, such as dislocations, which, while they are line defects in 3D, are point defects in 2D. The results are compared to the theories of melting of 2D crystals (spheres) and of 2D smectic liquid crystals (cylinders), a comparison that will allow us to understand most, but not all, of the features of these order-disorder transitions that occur as the temperature is increased.

Kramer, Edward J. (UCSB)

2010-10-08

449

Vertically aligned biaxially textured molybdenum thin films  

SciTech Connect

Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85 degrees with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85 degrees without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

Krishnan, Rahul [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Riley, Michael [Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lee, Sabrina [US Army Armament Research, Development and Engineering Center, Benet Labs, Watervliet, New York 12189 (United States); Lu, Toh-Ming [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2011-09-15

450

Solution Processed Graphene for Utilization in Thin Films  

NASA Astrophysics Data System (ADS)

Solution processing of graphene offers a method for increasing the purity and uniformity of the deposited thin films. Solubility parameters are useful in preparing dispersions and have been employed successfully with CNTs. Applying solubility parameters and solution processing techniques to graphene provides an avenue for both higher purity samples and more uniform thin films. The various families of solvents have different solubility parameters and careful selection of these parameters will help the quality of dispersions. Vacuum filtration and density centrifugation allow for filtering of the material, while annealing films is known to fix defects and improve structure. Through filtration, film deposition, and thermal annealing, graphene thin films of higher purity and uniformity will lead to graphene thin films that have the theoretical properties closer to ideal single crystal graphene. These properties have major applications in the fields of solar power and organic light emitting diodes as transparent electrodes and electron donor material.

Belew, Jonathan

2012-10-01

451

Irradiation-induced densification of cluster-assembled thin films  

NASA Astrophysics Data System (ADS)

The growth and modification of nanocluster-assembled thin films were studied using molecular-dynamics simulations. Porous thin films of copper were grown through sequential deposition of 50Cu711 nanoclusters on a Cu (100) substrate. Irradiation of these films with Xe and Au ions, at energies ranging 5-30 keV, was then carried out with the aim of increasing their density. Results show that heavy-ion irradiation can successfully be used in the densification of initially underdense thin films. With ion ranges tuned to the thickness of the thin films, densities approaching that of bulk copper were achieved at fluences as low as 50×1012ions/cm2 . Densification was caused by local melting in individual clusters and the resulting viscous flow of atoms into voids within the films. Nanocrystallinity was preserved as recrystallization occurred according to crystal orientations of the pre-existing clusters.

Meinander, K.; Nordlund, K.

2009-01-01

452

Porous thin films of functionalized mesoporous silica nanoparticles.  

PubMed

The synthesis of extremely small mesoporous silica nanoparticles via a specific co-condensation process with phenyl groups is demonstrated. The suspensions are ideally suited for the production of nanoscale thin films by spin-coating. Thanks to the small particle size and the resulting low surface roughness, the films show excellent optical qualities and exhibit good diffusion properties and a highly accessible pore system. The availability of such homogeneous porous thin films made it possible to use ellipsometric porosimetry (EP) as a convenient method to determine the effective porosity of the films on their original support without destroying it. It was possible to record sorption isotherms of the thin films with ellipsometry and to correlate the data with nitrogen sorption data of dried powders of the same material. The thin films showed very low refractive indices of around 1.2. PMID:19206399

Kobler, Johannes; Bein, Thomas

2008-11-25

453

Study on Surface Energy of Ultra-thin Film  

NASA Astrophysics Data System (ADS)

The dependences of surface energy on ultra-thin film thickness are investigated experimentally and theoretically. Langmuir-Blodgett (LB) film and perfluoropolyether (PFPE) lubricant on solid substrates are used as ultra-thin film samples. Surface energies as a function of film thickness are experimentally obtained from contact angle measurements. The theoretical equation of the dispersive component of the surface energy of ultra-thin film is derived from the corrected van der Waals pressure equation for a multilayered system proposed by the authors. The theoretical values are found to agree with the experimental values. The theoretical equation presented in this study is considered to be useful in predicting the surface energy of an ultra-thin film on a solid substrate.

Matsuoka, Hiroshige; Ono, Katsunori; Fukui, Shigehisa

454

Growth of magnetic thin films using CO 2 RESS expansions  

Microsoft Academic Search

A continuous-flow rapid expansion of supercritical solution (RESS) apparatus is used to grow thin iron oxide thin films under ambient and vacuum conditions. The magnetic thin films are produced by expanding a supercritical solution of ferric acetylacetonate (Fe(acac)3) and CO2 and directing the resulting supersonic jet onto both hot and cold silicon wafers. The concentration of the expanding solution is

Silvia De Dea; Dominic Graziani; David R. Miller; Robert E. Continetti

2007-01-01

455

Polycrystalline silicon conductivity modulated thin film transistors  

NASA Astrophysics Data System (ADS)

Polycrystalline silicon (poly-Si) thin-film transistors (TFTs) on glass has received significant attention for use in large area microelectronic applications. These applications include both niche and large volume applications such as printer drivers, image scanners, active-matrix liquid crystal displays (AMLCDs), electro-luminescent displays, plasma assisted displays, etc. Currently, the leading technology for these applications is amorphous-Si (a-Si) TFT. However, as the information content increases, a-Si technology encounters severe challenges due to its inherent low mobility, high parasitic capacitance, low aperture ratio, and non-compatibility to CMOS process. On the other hand, poly-Si technology offers high mobility, low parasitic capacitance, small size, CMOS compatibility, good stability, and uses the infrastructure of silicon science and technology. Thus, a simple low temperature poly-Si technology which allows large area system integration on panel will be in great demand for future high definition displays. However, it was found that poly-Si material properties vary with its method of preparation, its grain size, its surface roughness, and the nature and distribution of the inter-granular and bulk defects. Therefore, extensive studies are needed to optimize the key parameters such as the off-current, on-current, and breakdown voltage of the devices. These parameters can be optimized by means of material preparation as well as innovative device designs. In this thesis, three TFT structures were invented and fabricated using a simple low temperature poly-Si technology. With these novel structures, pixels, pixel drivers, and analog and digital peripheral circuits can all be built on the same glass substrate. This allows the ultimate goal of display systems on glass to be much more closer to reality. First, a high voltage transistor called the Conductivity Modulated Thin Film Transistor (CMTFT) is presented. Using this structure, the fundamental current pinching problem of the conventional high voltage offset drain TFT is completely eliminated. Experimental results show that the CMTFT can handle three orders of magnitude higher current than that of the conventional offset drain TFT while still providing low leakage current, high breakdown voltage, and fast switching speed. It is very suitable to be used as pixel drivers and high voltage printer drivers. In order to implement efficient pixel transistors and design analog peripheral circuits on glass, a second novel structure called the double-gate Elevated-Channel Thin Film Transistor (ECTFT) is invented. The ECTFT exhibits kink-free IV characteristics and low leakage current compared to the conventional uniform thin- and thick-film devices. Furthermore, the double-gate operation of the device provides much higher output current, high on/off current ratio, and steeper subthreshold slope compared to the uniform film devices. All of these result in efficient pixels and high performance analog devices to be built on glass. Finally, to further optimize the CMTFT using the ECTFT technology, a third novel structure called the double-gate Elevated Channel CMTFT (EC-CMTFT) is fabricated. Combining the advantages of elevated channel and conductivity modulation, the EC-CMTFT has a four times reduction in offset region resistance and a five times larger on/off current ratio compared to the CMTFTs.

Anish, Kumar K. P.

1997-09-01

456

Electrical conductivity of nanocrystalline ceria and zirconia thin films  

Microsoft Academic Search

The results of studies of the preparation, structure and electrical conductivity of ZrO2:16% Y and CeO2 thin films are presented. Dense films with grain size controlled in the region of 1–400 nm have been obtained on monocrystalline sapphire and polycrystalline Al2O3 substrates using a polymeric precursor spin coating method. The electrical conductivity of nanocrystalline thin films has been studied as

Igor Kosacki; Toshio Suzuki; Vladimir Petrovsky; Harlan U Anderson

2000-01-01

457

Stability of hydrogenated nanocrystalline silicon thin-film transistors  

Microsoft Academic Search

Hydrogenated nanocrystalline silicon thin-films were obtained by catalytic chemical vapour deposition at low substrate temperatures (150°C) and high deposition rates (10 Å\\/s). These films, with crystalline fractions over 90%, were incorporated as the active layers of bottom-gate thin-film transistors. The initial field-effect mobilities of these devices were over 0.5 cm2\\/V s and the threshold voltages lower than 4 V. In

A. Orpella; C Voz; J Puigdollers; D Dosev; M Fonrodona; D Soler; J Bertomeu; J. M Asensi; J Andreu; R Alcubilla

2001-01-01

458

Thin-film rechargeable lithium batteries for implantable devices  

Microsoft Academic Search

Thin films of LiCoOâ have been synthesized in which the strongest x-ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin-film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V

J. b. Bates; N. J. Dudney; C. F. Luck

1997-01-01

459

Reactivity of gold thin films grown on iridium: Hydrogen dissociation  

Microsoft Academic Search

Dissociative adsorption of H2 (D2) on Au thin films grown on an Ir{111} surface has been studied with temperature-programmed desorption using a quadrupole mass spectrometer and nuclear reaction analysis. Thin Au{111} films are epitaxially grown on Ir{111}, as confirmed by low-energy electron diffraction and scanning tunneling microscopy. H2 (D2) was dissociatively adsorbed on these Au{111} films, although it is well

Michio Okada; Shouhei Ogura; Wilson Agerico Diño; Markus Wilde; Katsuyuki Fukutani; Toshio Kasai

2005-01-01

460

Towards a thin films electrochromic device using NASICON electrolyte  

Microsoft Academic Search

The optimisation of the morphology of WO3 thin films allowed a more efficient electrochromic colouring using Na+ ions than H+ ones. Therefore, sodium superionic conductor (Na3Zr2Si2PO12, NASICON) films may be used as electrolyte in inorganic electrochromic devices. In this paper, the structure, chemical composition,\\u000a morphology and electrochromic properties of WO3, ZnO:Al and Na3Zr2Si2PO12 thin films were studied to develop a

D. Horwat; J. F. Pierson; A. Billard

2008-01-01

461

Interconnected Si nanocrystals forming thin films with controlled bandgap values  

SciTech Connect

Interconnected Si nanocrystals forming homogeneous thin films with controlled bandgap values from 1.2 to 2.9 eV were formed by pulsed plasma enhanced chemical vapor deposition technique under dusty plasma conditions. The chosen values of plasma duration time correspond to specific phases of the dust nanoparticle growth. Structural and optical properties of the deposited nanostructured films are described in details. These nanocrystalline Si thin films seem to be promising candidates for all-Si tandem solar cell applications.

Nychyporuk, T.; Zakharko, Yu.; Lysenko, V.; Lemiti, M. [Lyon Institut of Nanotechnologies (INL), CNRS UMR-5270, University of Lyon, INSA de Lyon, 7 avenue Jean Capelle, Bat. Blaise Pascal, 69621 Villeurbanne Cedex (France)

2009-08-24

462

Electrochromism in spray deposited iridium oxide thin films  

Microsoft Academic Search

Electrochromic iridium oxide thin films were deposited onto fluorine doped tin oxide coated glass substrates from an aqueous iridium chloride solution by pneumatic spray pyrolysis technique. The as-deposited samples were X-ray amorphous. The electrochromic properties of thin films were studied in an aqueous electrolyte (0.5N H2SO4) using cyclic voltammetry (CV), chronoamperometry (CA) and spectrophotometry. Iridium oxide films show pronounced anodic

P. S. Patil; R. K. Kawar; S. B. Sadale

2005-01-01

463

Compressibility of Thin Film Lubricants Characterized Using Atomistic Simulation  

Microsoft Academic Search

Compressibility of thin lubricating films remains incompletely understood. Molecular dynamics simulations of a polymeric fluid\\u000a confined in a nanoscale channel are used to investigate the effects of pressure and temperature on a thin film’s response\\u000a to compression. The observed trends are analyzed and compared to predictions of traditional, bulk fluid compressibility models.\\u000a At ambient temperatures and pressures, molecular dynamics and

Ashlie Martini; Ajay Vadakkepatt

2010-01-01

464

Thin Film Synthesis and Characterization of MAX-Phase Compounds  

Microsoft Academic Search

We present the synthesis and characterization of thin film MAX-phase compounds. Thin film synthesis was performed by magnetron sputtering from compound and elemental target materials on 2-inch c-axis sapphire wafers. A series of experiments were carried out where parameters of temperature, gas flow, pressure, and cathode power were varied. Films were characterized by Raman spectroscopy, electron microscopy, X-ray diffraction, and

T. H. Scabarozi; W. Tambussi; J. D. Hettinger; S. E. Lofland; M. W. Barsoum

2007-01-01

465

Interconnected Si nanocrystals forming thin films with controlled bandgap values  

NASA Astrophysics Data System (ADS)

Interconnected Si nanocrystals forming homogeneous thin films with controlled bandgap values from 1.2 to 2.9 eV were formed by pulsed plasma enhanced chemical vapor deposition technique under dusty plasma conditions. The chosen values of plasma duration time correspond to specific phases of the dust nanoparticle growth. Structural and optical properties of the deposited nanostructured films are described in details. These nanocrystalline Si thin films seem to be promising candidates for all-Si tandem solar cell applications.

Nychyporuk, T.; Zakharko, Yu.; Lysenko, V.; Lemiti, M.

2009-08-01

466

Photolithography I: Thin Film Deposition and Mask Design  

NSDL National Science Digital Library

In this lab, students design, fabricate and test four Al resistors using some of the techniques that are employed to make integrated circuits. First, students will evaporate a thin film of aluminum on a Si wafer. Then, they will use photolithographic techniques to pattern the film and etch away unwanted parts, leaving only your resistors. Students will complete the Al thin film deposition and mask design parts of the process. For the second part of this laboratory activity, click here.

Plisch, Monica; Huang, Kevin; Shull, Alison; Buhrman, Robert A.

2008-10-16

467

Thin film adhesion by nanoindentation-induced superlayers. Final report  

SciTech Connect

This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

Gerberich, William W.; Volinsky, A.A.

2001-06-01

468

Template engineering of Co-doped BaFe2As2 single-crystal thin films.  

PubMed

Understanding new superconductors requires high-quality epitaxial thin films to explore intrinsic electromagnetic properties and evaluate device applications. So far, superconducting properties of ferropnictide thin films seem compromised by imperfect epitaxial growth and poor connectivity of the superconducting phase. Here we report new template engineering using single-crystal intermediate layers of (001) SrTiO(3) and BaTiO(3) grown on various perovskite substrates that enables genuine epitaxial films of Co-doped BaFe(2)As(2) with a high transition temperature (T(c,rho=0) of 21.5 K, where rho=resistivity), a small transition width (DeltaT(c)=1.3 K), a superior critical current density J(c) of 4.5 MA cm(-2) (4.2 K) and strong c-axis flux pinning. Implementing SrTiO(3) or BaTiO(3) templates to match the alkaline-earth layer in the Ba-122 with the alkaline-earth/oxygen layer in the templates opens new avenues for epitaxial growth of ferropnictides on multifunctional single-crystal substrates. Beyond superconductors, it provides a framework for growing heteroepitaxial intermetallic compounds on various substrates by matching interfacial layers between templates and thin-film overlayers. PMID:20190768

Lee, S; Jiang, J; Zhang, Y; Bark, C W; Weiss, J D; Tarantini, C; Nelson, C T; Jang, H W; Folkman, C M; Baek, S H; Polyanskii, A; Abraimov, D; Yamamoto, A; Park, J W; Pan, X Q; Hellstrom, E E; Larbalestier, D C; Eom, C B

2010-02-28

469

The Characterization of Thin Film Nickel Titanium Shape Memory Alloys  

NASA Astrophysics Data System (ADS)

Shape memory alloys (SMA) are able to recover their original shape through the appropriate heat or stress exposure after enduring mechanical deformation at a low temperature. Numerous alloy systems have been discovered which produce this unique feature like TiNb, AgCd, NiAl, NiTi, and CuZnAl. Since their discovery, bulk scale SMAs have undergone extensive material property investigations and are employed in real world applications. However, its thin film counterparts have been modestly investigated and applied. Researchers have introduced numerous theoretical microelectromechanical system (MEMS) devices; yet, the research community's overall unfamiliarity with the thin film properties has delayed growth in this area. In addition, it has been difficult to outline efficient thin film processing techniques. In this dissertation, NiTi thin film processing and characterization techniques will be outlined and discussed. NiTi thin films---1 mum thick---were produced using sputter deposition techniques. Substrate bound thin films were deposited to analysis the surface using Scanning Electron Microscopy; the film composition was obtained using Energy Dispersive Spectroscopy; the phases were identified using X-ray diffraction; and the transformation temperatures acquired using resistivity testing. Microfabrication processing and sputter deposition were employed to develop tensile membranes for membrane deflection experimentation to gain insight on the mechanical properties of the thin films. The incorporation of these findings will aid in the movement of SMA microactuation devices from theory to fruition and greatly benefit industries such as medicinal and aeronautical.

Harris Odum, Nicole Latrice

470

Ferroelectric behavior in bismuth ferrite thin films of different thickness.  

PubMed

The ferroelectric behavior of BiFeO(3) thin films is modified by changing the film thicknesses, where the BiFeO(3) thin films with different thicknesses were grown on SrRuO(3)/Pt/TiO(2)/SiO(2)/Si(100) substrates by radio frequency sputtering. The mixture of (110) and (111) orientations is induced for all BiFeO(3) thin films regardless of their thicknesses, together with the columnar structure and the dense microstructure. Their dielectric behavior is almost independent of the film thickness where all thin films have a low dielectric loss. A giant remanent polarization of 2P(r) ? 156.6-188.8 ?C/cm(2) is induced for the BiFeO(3) thin films in the thickness range of 190-600 nm. As a result, it is an effective way to improve the ferroelectric behavior of the BiFeO(3) thin film by tailoring the film thickness. PMID:21861505

Wu, Jiagang; Wang, John; Xiao, Dingquan; Zhu, Jianguo

2011-08-30

471

Optical pump Terahertz probe transmission spectroscopy of YBCO thin films  

Microsoft Academic Search

Our facility uses optical pump THz probe transmission spectroscopy to study the quasiparticle dynamics in Yttrium Barium Copper Oxide (YBCO) thin films. The recovery of the film exhibits two components, a fast response on the order of several ps and a long tail that lasts nanoseconds. In this presentation, the behaviour of the film in both the fast and long

Anna Kristoffersen; John Nam

2005-01-01

472

MOLECULAR DYNAMICS SIMULATION OF THERMAL CONDUCTION IN NANOPOROUS THIN FILMS  

Microsoft Academic Search

Molecular dynamics simulations of thermal conduction in nanoporous thin films are performed. Thermal conductivity displays an inverse temperature dependence for films with small pores and a much less pronounced dependence for larger pores. Increasing porosity reduces thermal conductivity, while pore shape has little effect except in the most anisotropic cases. The pores separate the film into local regions with distinctly

Jennifer R Lukes; C. L. Tien

2004-01-01

473

Chemical Solution Routes to Single-Crystal Thin Films  

Microsoft Academic Search

Epitaxial thin films of inorganic single crystals can be grown on single-crystal substrates with a variety of different solution chemistries. This review emphasizes chemical solution deposition, in which a solution is used to deposit a layer of precursor molecules that decompose to low-density, polycrystalline films during heating. Ways to control film cracking during deposition and heat treatment and why many

F. F. Lange

1996-01-01

474

Plasma treatment for crystallization of amorphous thin films  

Microsoft Academic Search

The crystallization of amorphous metal oxide thin films was achieved by RF plasma treatment. Although various amorphous films are crystallized after 2 min or so, the sample temperature is lower than 150 °C without compulsory cooling even when the films are treated for 1 h. The oxygen gas pressure on the plasma treatment was found to be the key parameter

H. Ohsaki; Y. Shibayama; A. Nakajim; A. Kinbara; T. Watanabe

2006-01-01

475

Thin film processing by radio frequency hollow cathodes  

Microsoft Academic Search

The main features of the radio frequency (RF) hollow cathodes for thin film processing are summarized. The utilization of cylindrical RF hollow cathodes in both the plasma-enhanced chemical vapour deposition (PECVD) and the physical vapour deposition (PVD) of films is reviewed. An example of the high rate PECVD of Si–N films is described in more detail. Gas metastables excited inside

L. Bárdoš; H. Baránková; S. Berg

1997-01-01

476

Semiconducting thin films of zinc selenide quantum dots  

Microsoft Academic Search

A novel chemical route for deposition of zinc selenide quantum dots in thin film form is developed. The deposited films are characterized with very high purity in crystallographic sense, and behave as typical intrinsic semiconductors. Evolution of the average crystal size, lattice constant, lattice strain and the optical properties of the films upon thermal treatment is followed and discussed. The

Biljana Pejova; Atanas Tanusevski; Ivan Grozdanov

2004-01-01

477

Thin films of mixed metal compounds  

DOEpatents

Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.

Mickelsen, R.A.; Chen, W.S.

1985-06-11

478

Amperometric noise at thin film band electrodes.  

PubMed

Background current noise is often a significant l